chapter 12 endurance and ultra-endurance athletes

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12 Endurance and Ultra-endurance Athletes What is different about endurance athletes? What energy systems are utilized during endurance exercise? Are total energy needs for endurance athletes different than for other types of athletes? Are macronutrient needs different for endurance athletes? How important are carbohydrates to endurance athletes? Are protein needs different for endurance athletes? Should endurance athletes eat more fats to meet their energy needs? Are vitamin/mineral needs different for endurance athletes? Why are fluids critical to endurance performance? What meal planning/event logistics need to be considered during endurance events? © Jones and Bartlett Publishers. NOT FOR SALE OR DISTRIBUTION.

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Page 1: CHAPTER 12 Endurance and Ultra-endurance Athletes

12 Endurance andUltra-enduranceAthletes

� What is different about endurance athletes?

� What energy systems are utilized during endurance exercise?

� Are total energy needs for endurance athletes different than for other types of athletes?

� Are macronutrient needs different for endurance athletes?

� How important are carbohydrates to endurance athletes?

� Are protein needs different for endurance athletes?

� Should endurance athletes eat more fats to meet their energy needs?

� Are vitamin/mineral needs different for endurance athletes?

� Why are fluids critical to endurance performance?

� What meal planning/event logistics need to be considered during endurance events?

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Adam is a 14-year-old distance swimmer. He swims with a club team and competes reg-ularly. The team’s weekly yardage ranges from 30,000–35,000 yards with 2–3 days ofdry land exercises. Several months ago, Adam decided to cut out all junk food from

his diet in hopes of improving his swimming performance. After making the dietary change,his times for the 200 butterfly, 500 freestyle, and 1-mile freestyle began to improve and hewas feeling good! Another result of his dietary changes and hard efforts in the pool was a 28-pound weight loss in 6 months, dropping to a mere 140 pounds for his 5′11″ frame. Hismother and coach became concerned with his weight loss, afraid that he had lost too muchand was also losing muscle mass, which would eventually hurt his performance. In additionto these concerns, Adam was approaching the time for a switch to the high school team,which meant more yardage in the pool and more dry land exercises. Adam was open to eatingmore food to keep his weight and strength stable, but was unsure of how to do it in a healthyway.


� What are Adam’s daily calorie needs?

� Should Adam begin eating ice cream, candy bars, and other high-calorie “junk” foodsagain in order to increase his daily calorie intake?

� What advice would you give Adam?

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What is different about endurance athletes?

In general, endurance is one of the basic componentsof physical fitness. As a result, most athletes haveto possess some degree of muscular and cardiores-

piratory endurance to perform in theirrespective sports. Muscular enduranceis the ability of a muscle or group ofmuscles to repeatedly develop or main-tain force without fatiguing. Car-diorespiratory endurance is the abilityof the cardiovascular and respiratorysystems to deliver blood and oxygen toworking muscles, which in turn enablesthe working muscles to perform con-tinuous exercise. In other words, aperson who possesses good cardiores-piratory fitness will be able to performhigher intensity activity for a longer pe-riod of time than a person with poorcardiorespiratory fitness.

Obviously, endurance is importantto almost all athletes, even those involved in sportsrequiring short, intermittent bursts of intense anaer-obic activity that are repeated over the course of anhour or more. Because so many sports require en-durance, clarification is needed regarding which ath-letes fall into the category of “endurance and

ultra-endurance athletes.” For the pur-poses of this chapter, endurance ath-letes are those who are engaged incontinuous activity lasting between30 minutes and 4 hours. Ultra-endurance athletes are a subgroup ofendurance athletes that engage in ex-tremely long bouts of continuous ac-tivity lasting more than 4 hours.

Because of the duration and con-tinuous nature of their sports, en-durance athletes expend a tremendousnumber of calories not only duringcompetition, but also in their prepara-tory training. For example, energy ex-penditures of 6,000 to 8,000 kcals/dayare not out of the ordinary for ultra-endurance athletes. This puts a tremen-

dous drain on energy reserves that must bereplenished after daily training bouts, making diet akey factor not only for athletic success, but also for

overall health. Failure to maintain adequate dietaryintake of nutrients can quickly result in chronic fa-tigue, dehydration, increased risk for illness (e.g., up-per respiratory infection) and injuries, as well asmuscle wasting.

Although endurance sports require high calorieintakes, they do not give athletes a license to eat in-discriminately. Although eating enough calories tooffset the energy demands of their sport may some-times be difficult, athletes must pay careful attentionto dietary composition and the timing of consump-tion to help ensure their success. For the ultra-endurance athlete, not only is their training dietcrucial, but so is their nutrient consumption duringlengthy competitions. This chapter focuses on thedietary requirements of these “high caloric need” en-durance and ultra-endurance athletes.

What energy systems are utilized duringendurance exercise?

As with most sports, all three energy systems (i.e.,phosphagen, anaerobic, and aerobic) are workingto contribute energy during endurance exercise.However, the primary energy system relied uponduring endurance exercise is the aerobic system(shown on the right side of ). As discussedin Chapter 2, the chemical energy our bodies relyupon is adenosine triphosphate (ATP). The aero-bic energy system has an almost unlimited capac-ity for producing ATP. The downside is that theaerobic system cannot produce ATP very quickly;as a result, the speeds at which endurance and ultra-endurance activities are carried out are slower rel-ative to that of anaerobic athletes. However, withappropriately designed training programs, the aer-obic energy system of muscles can be improved, thusenabling higher rates of ATP production. The rateof aerobic ATP production is knownas aerobic power. The faster the rateof ATP production, the higher the aer-obic power demonstrated by that ath-lete. Elite endurance athletes exhibitremarkable aerobic power. They cansustain relatively high-velocity move-ments for hours that an untrained in-dividual may only be able to maintainfor several minutes before fatiguing.

Figure 12.1

muscular endurance Theability of a muscle orgroup of muscles torepeatedly develop ormaintain force withoutfatiguing.

cardiorespiratoryendurance The ability ofthe cardiovascular andrespiratory systems todeliver blood andoxygen to workingmuscles, which in turnenables the workingmuscles to performcontinuous exercise. It isan indicator of aperson’s aerobic orcardiovascular fitness.

endurance athlete Anathlete who participatesin sports involvingcontinuous activity (30 minutes to 4 hours,as defined in thischapter) involving largemuscle groups.

ultra-endurance athleteA subgroup ofendurance athletes thatengage in extremelylong bouts ofcontinuous activitylasting more than4 hours. Ironmantriathletes and ultra-marathoners areexamples of this groupof endurance athletes.

aerobic power The rateof aerobic ATPproduction. It is usuallyrepresented by thefastest pace or rate ofphysical activity anathlete can sustain andis an indicator ofcardiorespiratory fitness.

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Are total energy needs for endurance athletes different than for other types of athletes? 363

Are total energy needs for enduranceathletes different than for other types of athletes?

One of the main concerns for endurance athletes ismatching energy consumption with energy expen-diture. Long distance, strenuous exercise requires alarge number of calories. Elite athletes can poten-tially burn more than two to three times the numberof calories as their untrained, weight-matched coun-terparts. If these calories are not replaced daily, en-ergy for training and the ability to perform duringcompetitions will decline.

How are daily energy needs calculated for enduranceathletes?To estimate the total energy needs for an enduranceathlete, use the resting energy expenditure (REE)equations presented in Chapter 10 and reviewed inTable 12.1.

For example, Bill is a 35-year-old marathoner,running 60–80 miles a week. His weight has beenstable at 140 pounds for the last 12 months. Usingthe calculation presented in Table 12.1, Bill’s dailycalorie needs are:

1. Calculation for 35-year-old men: REE = (11.6 × BW) + 879

2. Convert pounds of bodyweight to kilograms = 140 ÷2.2 = 63.6 kilograms

3. Bill’s REE = (11.6 × 63.6 kg)+ 879 = 737.8 + 879 =1,616.8 calories

4. Multiply the REE by the ac-tivity factor of 1.6–2.4 =1,616.8 × (1.6–2.4) = 2,587–3,880 calories per day

The daily calorie range calcu-lated for Bill is quite large—a dif-ference of 1,293 calories. Bill canuse this range to adjust his intakebased on his daily volume of run-ning. Rest and recovery days willrequire approximately 2,500–2,800 calories,w h e r e a shigh mile-

age or hard workout days willrequire an intake of 3,600–3,900 calories. With a weeklymileage of 60–80 miles, Bill isrunning about 10–12 miles aday. Therefore, on most dayshe will need to consume a dietproviding calories at the highend of his estimated range in




100 mdash

(~100% anaerobic)




200 mswim


% anaerobic

% aerobic

Key (40:60)

2-mile run


Cross countryrunning (10:90)




Rowing2000 m(40:60)

The anaerobic-aerobic continuum. The primary energy system relied uponduring endurance exercise is the aerobic system.

Figure 12.1

12.1 Resting Energy Expenditure (REE) Calculations and Activity Factors

Gender Equation Activity and Age (BW in kilograms) Factor

Males, 10–18 years REE = (17.5 × BW) + 651 1.6–2.4

Males, 18–30 years REE = (15.3 × BW) + 679 1.6–2.4

Males, 30–60 years REE = (11.6 × BW) + 879 1.6–2.4

Females, 10–18 years REE = (12.2 × BW) + 749 1.6–2.4

Females, 18–30 years REE = (14.7 × BW) + 496 1.6–2.4

Females, 30–60 years REE = (8.7 × BW) + 829 1.6–2.4

Source: World Health Organization, Report of a JointFAO/WHO/UNU Expert Consultation.37

gaining the performance edge

Knowing how to estimatethe daily energy needs foran endurance athlete is acrucial first step todeveloping a dietary planthat provides enoughcalories to meet trainingand competition energyneeds.

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order to perform well and recover completely fromworkouts.

Even though the activity factors of 1.6–2.4 willcover most recreational and competitive athletes, therange may not estimate calories appropriately for allathletes. For example, cyclists participating in stagedraces that last from 1 to 3 weeks may burn caloriesin the 7,000–8,000 calorie per day range. If Bill, fromthe previous example, was a stage racing cyclist, toreach this calorie range, an activity factor of 4.3–4.9would be appropriate. On the other end of the spec-trum, endurance athletes who want to lose weightmay find that an activity factor of 1.4–1.6 estimatesan appropriate calorie level. Therefore, use the cal-culation guidelines while also making individualizedadjustments for specific athletes.

It can sometimes be challenging for athletes toincrease their daily intake to match their actual caloricneeds. Training, work/school, sleep, and other non-sport activities take time away from preparing andeating meals and snacks. Some athletes also com-plain about feeling too full and not being able tocomfortably add more calories to meet their needs.Also, strenuous effort during training or competi-tion tends to decrease appetite, causing athletes toeat small meals and snacks. Athletes in these situa-

tions are looking for quick, easy, and nutrient-denseways to increase their calories while enjoying theirfood and not spending all day in the kitchen. Mealplans should be created that fit the daily scheduleof the athlete and incorporate nutrient- and calorie-dense meals/snacks that are within the cooking/preparation skills of the athlete.

When planning meals for individuals needing toincrease calories, a balance of macronutrients is es-sential. If an athlete increases mainly carbohydrate-and fiber-rich foods, the result is a feeling of fullnessand bloating. If protein-rich foods are the focus, theendurance athlete may neglect to fully replenish glyco-gen stores, ultimately hindering training and racing.Too many fat-rich foods can delay gastric emptying,potentially disrupting training sessions due to a senseof fullness, stomach cramps, or diarrhea. By bal-ancing the macronutrients and increasing carbohy-drates, protein, and fat in proportional amounts,athletes can reap the benefits of increasing total calo-rie intake while feeling good and performing well.

Training Table 12.1 presents sample meal plans forthree different calorie levels—3,000, 4,000, and 5,000calories. Note that as the number of calories increases,the frequency of meals and snacks increases as dothe number of calorie-dense foods. Three meals plus

Training Table 12.1: Example Menu Plans for 3,000, 4,000, and 5,000 Calories

Meal/Snack Food/Beverage Carbohydrate Content (g)

Breakfast 2 cups raisin bran 941 cup skim milk 121 banana 28

Lunch 4 oz turkey and cheese sandwich 27

6 oz low-fat yogurt 341⁄4 cup trail mix 231 plum 91 apple 21

During workout 20 oz sports beverage 48

Postworkout snack 1⁄2 peanut butter sandwich 1512 oz chocolate milk 39

Dinner 2 cups pasta 783⁄4 cup marinara sauce 156 oz chicken breast 02 cups steamed broccoli 912 oz skim milk 18

Total Calories = 2,973 Total carbohydrates = 470 g61% of total calories

3,000 Calories

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Training Table 12.1 Continued

Meal/Snack Food/Beverage Carbohydrate Content (g)

Breakfast Smoothie:2 frozen bananas 552 cups skim milk 242 scoops protein powder 27

Snack Orange 15Granola bar 29

Lunch 2 cups chili 544 oz roast beef sandwich 252 cups fruit salad 61

During workout 32 oz sports beverage 76

Postworkout snack 6 oz yogurt 341⁄2 cup dry cereal 13

Dinner 6 oz salmon 02 cups wild rice 703 cups salad with dressing 1716 oz skim milk 24

Snack 11⁄2 cups frozen yogurt 731⁄2 cup frozen blueberries 9

Total Calories = 4,016 Total Carbohydrates = 606 g59% of total calories

Meal/Snack Food/Beverage Carbohydrate Content (g)

Breakfast 2-egg omelet with cheese 52 pieces of toast with 1 T butter 4712 oz orange juice 39

Snack 1 cup mixed nuts and raisins 67

Lunch 2 hamburgers with buns 6916 oz skim milk 242 pieces fresh fruit 52

Snack Smoothie:2 cups frozen mixed fruit 421 cup pineapple juice 358 oz yogurt 462 scoops protein powder 27

During workout 48 oz sports beverage 114

Dinner 2 pieces lasagna 752 pieces garlic bread 262 cups green beans and carrots 2216 oz skim milk 24

Snack 8 oz skim milk 123 oatmeal raisin cookies 23

Total Calories = 4,992 Total Carbohydrates = 749 g59% of total calories

5,000 Calories

4,000 Calories

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several snacks distributes caloric intake through-out the day, preventing athletes from feeling “stuffed”or uncomfortable after eating. Calorie-dense foodsincrease energy intake considerably, without largeincreases in the volume of food consumed.

How many calories should be consumed duringendurance training or competition?The number of calories expended while participat-ing in endurance sports varies. The energy require-ments for an individual can be estimated based onthe sport, the intensity and duration of activity, andthe body weight of the athlete. However, often it isnot physically or logistically possible for an athleteto fully match his or her energy expenditure with in-take while exercising. Movement (e.g., running, bik-ing), mental focus (e.g., mountain biking, race cardriving), and lack of feasibility (e.g., swimming, row-ing) can create circumstances where athletes are un-able to meet their calorie needs. It can not only beextremely challenging for an athlete to physicallyconsume enough food to match energy expenditure

during activity, but also diffi-cult for the body to digesthigh volumes of food withoutdeveloping nausea or cramp-ing. Therefore, it is more prac-tical and realistic to developa plan based on the nutritionbasics needed for enduranceperformance: carbohydrates,fluids, and sodium.

For example, a 125-pound half-marathoner run-ning a 6:30 minute/mile pacewill burn approximately775 calories in 1 hour of con-tinuous running.51 If this ath-

lete were trying to match hisenergy needs by consuming a sports beverage (con-taining 50 calories per 8 ounces), he would need todrink 124 fluid ounces in 1 hour! An average rangeof fluid intake that can be consumed comfortablyand safely for most athletes is approximately 24–48ounces per hour—three to five times this amount isneeded to obtain 775 calories. However, if the nu-trition plan was based on fluid and carbohydrateneeds, the requirements could be easily met. As men-tioned in Chapter 3, it is recommended that athletesconsume approximately 1.0–1.1 grams of carbo-hydrates per minute during exercise. Therefore, thisathlete would need 60–66 grams of carbohydrates

per hour. Assuming the sports beverage used con-tains 14–15 grams of carbohydrates per 8 fluidounces, the runner would need to drink only about34 fluid ounces per hour to meet his carbohydrateneeds. Thirty-four fluid ounces per hour is muchmore manageable than 124 fluid ounces.

How many calories are required after a training sessionor competitive event?A general guideline for endurance athletes is to con-sume 200–300 calories immediately following a train-ing session or competitive event. This small snackshould be followed by a substantial meal withinthe next 1 to 2 hours, supplying more calories,macronutrients, micronutrients, and fluids. Two hun-dred to three hundred calories is not a large amountof food and can be easily obtained by eating half ofa sandwich, a large glass of milk, or a glass of 100%juice. Often, athletes complain of not wanting to eatimmediately following exercise—especially intenseexercise. However, the suggestion of consuming asmall snack versus a full meal is often perceived asmore manageable, is generally well-tolerated, andputs the recovery wheels in motion.

Are macronutrient needs different for endurance athletes?

The main difference between the diets of enduranceathletes and those of athletes in other sports is inthe quantity of food consumed, not necessarily themacronutrient composition of the diet. The extremecaloric demand of long-duration training, day in andday out, stresses the body’s energy reserves, particu-larly the glycogen stores. Therefore, carbohydratesplay a key role in the endurance athlete’s diet. Simi-lar to other athletes with high calorie needs, dietaryfats are valuable for providing extra calories in a smallvolume of food. Another consequence of high calo-rie demands that is unique to endurance athletes isthe use of protein for energy production. Proteins arenot typically used by the body for energy production;however, they can play an energetic role, contribut-ing up to 15% of the calories required during en-durance and ultra-endurance sports. The bottom lineis that endurance athletes need the same macronu-trients as other athletes except in larger quantities sothat the energy requirements of their sport can bemet. The upcoming sections will outline more spe-cific recommendations and guidelines for carbohy-drate, protein, and fat intakes for endurance andultra-endurance athletes.

gaining the performance edge

Matching energyexpenditure during exercisewith energy intake may notbe practical or feasible forendurance and ultra-endurance athletes. It ismore important to developa nutrition plan that focuseson the performancerequirements ofcarbohydrates, fluids, andsodium rather thanachieving energy balance.

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How important are carbohydrates to endurance athletes? 367

How important are carbohydrates to endurance athletes?

Carbohydrates are crucial to endurance athletes notonly because they are an important energy source,but also because carbohydrates play a role in therapid metabolizing of fats for energy. If the liver andmuscles are depleted of glycogen, the endurance ath-lete experiences extreme fatigue (see ).

This is called “hitting the wall,” alsoknown as bonking. When bonking oc-curs the athlete can no longer generatethe energy needed to maintain his orher race pace and his or her perceptionof effort is greatly increased. The endresult is a catastrophic decrease inperformance.

Carbohydrate stores in the bodyare limited, and because of the long-duration and repetitive muscle activity

involved with endurance training and sport perfor-mance, the need for carbohydrates is increased. Infact, the time to exhaustion during endurance exer-cise is directly related to the initial levels of storedglycogen in the muscles (see Figure 3.8 in Chapter 3).In addition, carbohydrates are also necessary fornormal functioning of the central nervous system.Maintenance of blood glucose levels is importantin preventing mental fatigue because nerve cells relyon blood glucose for energy. For these reasons, it isdifficult to overstate the importance of adequate car-bohydrate intake for daily training as well as per-

Figure 12.2

formance in competition. For the endurance athlete,carbohydrates are truly the “master fuel.”

How are daily carbohydrate needs calculated for endurance athletes?Current daily carbohydrate recommendations forendurance athletes range from 5–10 grams of car-bohydrates per kilogram of body weight.8,40,41 Ap-plying this recommendation for Tony, a moderatelyactive, 22-year-old male who weighs 150 pounds:

150 pounds ÷ 2.2 = 68.1 kilograms (kg) of body weight

68.1 kg ÷ 5–10 g of carbohydrate per kg = 340–680 g of carbohydrates per day

The recommended 340–680 grams is a largerange! To narrow the recommendation for practicalpurposes, the calculated carbohydrate requirementsneed to be compared to the total calorie requirementsof the athlete. Using the equation from Table 12.1,Tony’s calorie needs are estimated to be 2,753–3,442calories per day:

1. REE = (15.3 × BW) + 679

2. REE = (15.3 × 68.1) + 679 = 1,721

3. Tony’s total energy needs = REE × activity factor= 1,721 × (1.6–2) = 2,753–3,442 calories per day

To establish a narrower range for a carbohydraterecommendation, determine the percentage of totalcalories coming from carbohydrates at each end ofthe spectrum. For example, knowing that each gramof carbohydrates has 4 calories, 340 grams of car-

bohydrates equals 1,360 calories, which is about50% of 2,753 calories. Endurance athletes shouldgenerally aim for 50%–65% of their total caloriesfrom carbohydrates. Therefore, the recommenda-tion of 340 grams of carbohydrates providing 50%of the estimated total daily calories is appropriate.However, the high end of the carbohydrate rec-ommendation would not be appropriate for a2,753-calorie diet, supplying nearly 99% of totalcalories (680 grams × 4) ÷ 2,753) × 100 = 99%!Even at the high end of the estimated calorie range(3,442 calories), 680 grams of carbohydrate wouldbe supplying 79% of the total calories, which isgenerally too high for a balanced daily diet. Ath-letes should aim to meet both total calorie and car-bohydrate requirements while maintaining abalance of all macronutrients. Recommendationsfor carbohydrates, as well as protein and fat, shouldalways be compared to total calorie estimations.





en (




Exercise time (h)

Perceived fatigue

Muscle glycogen (mmol/kg)

Blood glucosedepletion

Muscle beginsto use bloodglucose

Liver glycogen converted toglucose










0 1 2 3 4


Perceived fatigue



Glycogen depletion and the sensation of fatigue. If theliver and muscles are depleted of glycogen, the endurance athleteexperiences extreme fatigue.

Figure 12.2

bonking A condition inwhich the enduranceathlete experiencesextreme fatigue and aninability to maintain thecurrent level of activity.It is also known as“hitting the wall” andresults when the bodyhas depleted muscleand liver glycogenlevels.

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How should endurance athletes carbohydrate loadbefore competition?Carbohydrate loading is often cited as an effectiveway of maximizing muscle glycogen stores prior toan endurance event. As noted earlier, increasing mus-cle glycogen levels can increase the time to exhaus-tion and thus prevent or delay bonking (see Figure 3.8in Chapter 3). In the 6 to 7 days leading up to a com-

petition, endurance athletes should betapering and resting their muscles.When tapering, endurance athletes de-crease the volume and intensity of theirtraining. During the taper, the per-centage of carbohydrates consumedeach day should slowly increase fromabout 45%–55% of total calories to65%–70%. This progression allowsfor carbohydrate storage within the

muscles to be maximized while training time is min-imized. The combination of rest and a full fuel tankproduces an athlete who is mentally and physicallyfresh and nutritionally energized for race day.

A carbohydrate intake of approximately 8–10grams of carbohydrates per kilogram of body weight,or about 500–600 grams of carbohydrates per day,is required to maximize glycogen stores. However,a further increase in carbohydrate intake may notnecessarily further increase glycogen stores. Costillet al.8 found that glycogen stores were similar whenathletes consumed either 525 grams or 650 gramsof carbohydrates per day. This study suggests thatcarbohydrate intake greater than 600 grams per daymay not provide additional ergogenic benefits. Fora 150-pound athlete, a range of 8–10 grams of car-bohydrates per kilogram of body weight can be cal-culated as follows:

1. Convert pounds to kilograms: 150 ÷ 2.2 = 68.2 kg

2. Calculate carbohydrate needs: 68.2 kg × 8–10grams carbohydrates/kg = 546–682 grams ofcarbohydrates per day

Because research has shown that consumptionof greater than 600 grams of carbohydrates per daymay not be beneficial, it should be recommendedthat this 150-pound athlete consume 546–600 gramsof carbohydrates in the days leading up to a com-petition. If the athlete feels that energy is runninglow during workouts, or recovery is slow, then thegrams of carbohydrates can be increased graduallyuntil an ideal quantity within the range is realized.Training Table 12.1 uses the 3,000-, 4,000-, and

5,000-calorie per day example menus to demonstratethe quantity of food needed to reach approximately500–600 grams of carbohydrates per day.

During a tapering period, the decrease in calo-rie expenditure in the days leading up to an eventneeds to be realized and factored into a carbohydrateloading plan. The percentage oftotal calories contributed bycarbohydrates should increasein the days leading up to anevent, approaching 8–10 gramsof carbohydrates per kilogramof body weight. However, dueto a decrease in calorie needs,total calories need to be cut inorder to prevent weight gainand a feeling of sluggishness.The best way to decrease calo-ries without sacrificing overallnutrition and the nutrients for recovery is to cut backon fat intake temporarily (until the event). Protein isneeded to repair muscle tissueand therefore should not be de-creased dramatically in order tocut calories. Because fiber intakeshould be moderated in the daysleading up to an event, juices,milk, smoothies, and other liq-uid forms of carbohydrates areideal for use during a taper.

tapering A scheduleddecrease in the volumeand intensity of training6 or more days prior tocompetition. Thepurpose is to allow forrecovery from trainingand replenishment ofglycogen stores in theliver and muscle.

gaining the performance edge

Keep in mind that thesuggested range of500–600 grams ofcarbohydrates is not anabsolute number for allathletes. Daily nutritionplans must be developedon an individual basis andrecommendations may fallabove or below this range.

gaining the performance edge

Juices, milk, smoothies, andother liquid forms ofcarbohydrates are ideal forendurance athletes duringa taper and carbohydrateloading.

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How important are carbohydrates to endurance athletes? 369

Athletes who are competing several times a weekdo not have time to taper for 7 days while increas-ing carbohydrate intake. These athletes should en-sure an adequate consumption of carbohydrates ona daily basis, which can also effectively keep glyco-gen stores near their maximum.

Should carbohydrates be consumed in the hours or minutes prior to endurance activities?Research has demonstrated that consuming car-bohydrates in the hours leading up to an endurancetraining session or competition is critical for op-timal performance, especially during activitieslasting longer than 2 hours.9,17 Carbohydrates con-sumed prior to exercise increase blood glucose,which leads to a sparing of muscle and liver glyco-gen, thus enhancing endurance performance. Thequestion for endurance athletes is not if they shouldconsume carbohydrates prior to exercise, but ratherwhen and how many carbohydrates should beconsumed.

Even though it appears obvious in the researchthat pre-exercise carbohydrate consumption canprevent fatigue, the reality is that many athleteschoose to forego consuming any food, including car-bohydrates, prior to training or competitions. Ath-letes need to be educated on the detrimental effectsof this behavior. After an overnight fast, liver glyco-gen stores are depleted, which can lead to prema-ture fatigue during exercise.35 Some athletes justifynot consuming carbohydrates before training be-cause they plan to consume carbohydrate-rich sportsbeverages, gels, or bars during exercise. Althoughconsuming these products during exercise is clearlyadvantageous, it does not completely negate the needfor a pre-exercise meal.6

A recent study by Chryssanthopoulos et al.7 ex-amined the effects of a pre-exercise meal and car-bohydrate consumption during endurance runningas compared with running on an empty stomach (nopre-exercise meal) and no carbohydrate supple-mentation during exercise. The authors reported a9% increase in running capacity when a meal (con-taining 2.5 grams of carbohydrates per kilogram ofbody mass) was eaten 3 hours prior to exercise ver-sus when no meal was consumed. An additionalendurance benefit (22% increase) was observed whenthe subjects ate a carbohydrate-rich meal 3 hoursprior to exercise and consumed a 6.9% carbohydratebeverage during running, as compared to those whodid not eat a pre-exercise meal and did not drink thesports beverage during running. Endurance ath-

letes are encouraged to consume a well-rounded,carbohydrate-rich pre-exercise meal, and then con-tinue consuming carbohydrates during exercise inorder to optimize performance.

When is the ideal time to consume carbohydratesprior to endurance training or competition?The ideal time for consuming carbohydrates prior toexercise has been debated. Popular thought has ledto the recommendation of consuming carbohydrate-rich foods in the 2–4 hours leading up to exerciseand avoiding carbohydrates, specifically highglycemic foods/beverages such as glucose, in the hourimmediately prior to activity. The reasoning for thisadvice has been that the combined effects of insulin(secreted in response to the high glycemic index prod-ucts) and muscle contraction mediated glucose up-take (physical activity) would result in hypoglycemiaimmediately prior to or at the onset of exercise andthus negatively affect performance. However, a re-view of the current literature has revealed that onlyone study has reported a decrease in performance,whereas a majority of the studies have shown ei-ther no impact or enhancement of up to 20% on sub-sequent endurance performance.21

A recent article studying the impact of precar-bohydrate feedings on a series of 4,000-meter swimsperformed by triathletes confirmed a positive impacton performance when carbohydrates are consumedwithin an hour of exercise. Smith et al. (2002) ex-amined the effect of consuming a 10% glucose so-lution 5 minutes prior to a 4,000-meter swim, thesame solution 35 minutes prior to the swim, or theequivalent volume of a placebo, on swim time tocompletion. Although no statistical significance wasfound between the trials, the findings were mean-ingful, revealing a difference ranging from 24 sec-onds to 5 minutes in 8 out of the 10 subjects studiedwhen either glucose protocol was followed comparedwith placebo. The reported time difference wouldmake an impact on the finalplacement of a triathlete per-forming a similar distanceswim in an Ironman distancerace (3.8 km swim distance).

The timing of a pre-exercisecarbohydrate meal will varygreatly based on the quantityof carbohydrates consumedand an athlete’s individual tol-erance. Athletes typically con-sume their pre-exercise meal as

gaining the performance edge

Endurance athletes shouldexperiment and aim to eatfar enough in advance thatfood digests well beforecompetition, thusminimizing stomach andintestinal discomfort, butnot so far in advance thathunger ensues.

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close as 30 minutes before the initiation of enduranceexercise to as long as 4 hours prior. In general, thegreater the quantity of carbohydrates consumed, thelonger an athlete should leave between eating andthe beginning of an exercise session. It has been sug-gested that athletes consume greater than 2 gramsof carbohydrates per kilogram of body weight priorto endurance exercise in order to have a positive im-pact on performance.15,16 For a female enduranceathlete weighing 125 pounds, the quantity of car-bohydrates required prior to a long-duration train-ing session or competition would be 114 grams,calculated as follows:

1. Convert pounds to kilograms = 125 ÷ 2.2 =56.8 kg of body weight

2. The minimum amount of carbohydrates neededprior to exercise = 2 × 56.8 kg = 114 g

As noted in the 3,000-calorie meal plan presentedin Training Table 12.1, 114 grams can easily be ob-tained by eating 2 cups of raisin bran, 1 cup of skimmilk, and a banana, which provides a total of 133grams of carbohydrates.

Once an athlete knows the optimal quantity ofcarbohydrates to eat before endurance training, theathlete can then experiment with varying time peri-ods between eating and exercise. The athlete shouldaim to eat far enough in advance to ensure the fooddigests well before exercising, thus minimizing stom-ach and intestinal discomfort, but not so long thathunger ensues. Therefore, the optimal timing of apre-exercise carbohydrate-rich meal or snack will ul-timately be determined by each athlete.

Should the endurance athlete consume carbohydratesduring endurance activities?As glycogen stores in the body are depleted, musclesrely more heavily on blood glucose for fuel, espe-cially after 2–4 hours of continuous physical activ-ity.10 In order to maintain blood glucose for oxidationand continued energy production, athletes need toingest carbohydrates while exercising. Although con-suming enough carbohydrates during exercise canenhance endurance performance, ingesting too manycarbohydrates can lead to stomach cramping, in-testinal discomfort, and diarrhea, all of which canhinder performance. It is critical that athletes knowtheir carbohydrate needs during activity and prac-tice the ingestion of carbohydrate-rich foods and flu-ids during training to establish a nutrition plan basedon personal preferences and tolerances.

As stated earlier in this chapter, carbohydrateneeds during exercise are estimated at 1.0–1.1 gramsof carbohydrates per minute of activity, or 60–66grams of carbohydrates per hour. Some athletes caneasily consume and digest upwards of 75–85 gramsof carbohydrates per hour, whereas others can barelystomach 45–55 grams. Athletes need to experimentwith varying quantities of carbohydrates surroundingthe 60–66 gram range to determine the best estimatefor them individually. Carbohydrates can be con-sumed through a variety of foods and fluids such assports drinks, energy bars, energy gels, fruits, gra-nola bars, fig cookies, and even sandwiches. In ad-dition to individual preferences, a nutrition planneeds to be developed with the limitations of thesport in mind. Refer to the section “What meal plan-ning/event logistics need to be considered during en-durance events?” at the end of this chapter for severalexamples of nutrition plans developed to meet thenutritional needs of endurance athletes while fac-toring in the inherent limitations of the sport.

Is carbohydrate intake important during the recoveryperiod after endurance training or competition?Carbohydrates are critical for recovery from en-durance exercise. Repeated exercise sessions of longduration can deplete muscle glycogen stores. If glyco-gen stores are not replenished, performance in sub-sequent training or competitive sessions will suffer.Carbohydrates should be consumed as soon as pos-sible after exercise in adequate amounts for glyco-gen replenishment, based on individual needs.

To optimize the replenishment of glycogen af-ter endurance exercise, carbohydrates should be con-sumed as soon as possible after exercise—ideallywithin 15–30 minutes after exercise. The short timebetween cessation of exercise and carbohydrate con-sumption allows for digestion, absorption, and de-livery of carbohydrates to the muscles for storagewhen muscles are most receptive to glycogen stor-age. Endurance athletes who train daily at high in-tensity levels or for a long duration need to consumeadequate amounts of carbohydrates within this timeframe to be prepared for the next exercise session.

Endurance athletes should consume approxi-mately 1.1 grams of carbohydrates per kilogramof body weight (0.5 grams/pound) within 15–30minutes after exercise. For example, a 130-poundathlete in training for a marathon should consumeapproximately 65 grams of carbohydrates after ex-ercise, and a 160-pound marathoner would need 80grams of carbohydrates. Whenever possible, ath-

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letes should focus on consuming whole food car-bohydrates, juices, and low-fat dairy products tomeet postexercise carbohydrate needs. Some ath-letes are not hungry after a long exercise session andmay feel uncomfortable eating within 30 minutesafter exercise cessation. In this case, athletes canconsume high-carbohydrate beverages that areusually more tolerable than whole foods. This en-courages rehydration as well as carbohydrate re-plenishment. Table 12.2 provides some examples ofboth fluid and whole food combinations of carbo-hydrate sources to help endurance athletes meet theirneeds immediately postexercise. By following theguidelines for both the amount and timing of car-bohydrate consumption after endurance exercise,athletes will recover quickly and perform well intheir next training session.

There are many supplements marketed to en-durance athletes for recovery from training ses-sions and competitive events. Before purchasingand using one of these supplements, consider thefollowing:� How much carbohydrate is supplied in the

supplement? Some of the recovery supple-ments do not provide an adequate amount ofcarbohydrates. Athletes should calculate thenumber of grams they require and then deter-mine whether the supplement is adequate.

� What are the levels of other nutrients in thesupplement? Look on the Supplement Facts

label for the %DV (% Daily Value) of the vari-ous nutrients supplied in one serving of theproduct. If specific vitamins or minerals arepresent in quantities greater than100%–200% DV, the quantities are excessiveand in general should be avoided.

� How much does the supplement cost? Supple-ments of any kind can cost two to three timesas much as whole foods, milks, and juices. Ifan athlete is on a limited budget, whole foodsare generally more affordable and often supplya variety of nutrients.

� Are foods and beverages available? Supple-ments, especially those that do not require re-frigeration, are very usefulwhen athletes are travel-ing or away from home.Powders, bars, and liq-uids can be transportedeasily, carried in a gearbag, and consumedquickly after exercisewhen other options arenot available. However, ifwhole food, juice, ormilk/alternative optionsare available, athletesshould choose these itemsover supplements.

Are protein needs different for enduranceathletes?

The dietary protein requirement for athletes has beena subject of debate for years, particularly for strengthand power athletes. However, protein is importantto the endurance athlete as well. Contrary to popu-lar belief, recent research suggests that enduranceathletes may actually require more protein than theirresistance training counterparts. Tarnopolsky et al.43

found that endurance athletes required approximately1.4 grams of protein per kilogram of body weight inorder to maintain nitrogen balance—a level higherthan that needed by the resistance-trained subjectsin the study. Although endurance athletes do not pos-sess or strive to build the muscle mass of strengthand power athletes, research has clearly demonstratedthat endurance training results in increased proteinturnover in the body. The trauma of repeated con-tractions and high impact activities can increase pro-tein breakdown during exercise. Additionally, becauseof the huge energetic demands of endurance training

12.2 Sample Postexercise Carbohydrate Options

Food Carbohydrates (in grams)

1 orange 151 cup soy milk 152 sheets graham crackers 202 small fig cookies 221 cup animal crackers 241⁄2 cup applesauce 251 cereal bar 251 cup chocolate milk 261⁄2 whole grain bagel 261 cup apple juice 271 whole banana 281 cup cranberry juice 361 cup fruit yogurt 4012 oz carbohydrate energy drink 78

Note: Combine a high carbohydrate fluid with a high carbohy-drate solid food to obtain approximately 0.5 g carbohydratesper pound of body weight within 30 minutes after exercise.

gaining the performance edge

Carbohydrates are truly themaster fuel for enduranceathletes. Individual needsshould be calculated fordaily consumption, as wellas for before, during, andafter training. Through trialand error, athletes willdiscover their individualtolerances, which shouldbe built into the overallnutrition plan.

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it is now realized that some proteins are mobilizedfor energy. Protein is not typically used as a sourceof energy for the body; however, when caloric ex-penditure is high, the body will turn to proteins tosupplement its energy needs. This reliance on pro-teins for energy is exacerbated when an athlete’s dietis not adequate to maintain energy balance and/orcarbohydrate intake is low. After endurance exer-cise, protein synthesis has been shown to increase10%–80% within 4–24 hours.4 Due to the rise inprotein catabolism during activity and protein syn-thesis after exercise, appropriate daily protein intakeis important. Endurance athletes should focus onconsuming adequate quantities of protein daily toachieve a positive protein balance, which is impor-tant for muscle maintenance and recovery after dailytraining and competition.

How are daily protein needs calculated for enduranceathletes?Several factors need to be considered when deter-mining daily protein needs for endurance athletes.A general recommendation proposed by Lemon30,31

based on a review of the literature, as well asTarnopolsky et al.’s finding stated previously, sug-gests endurance athletes should aim to consume 1.1to 1.4 grams of protein per kilogram of body weightdaily. Others have recommended a higher daily in-take ranging up to 1.8–2.0 grams per kilogram ofbody weight for a greater safety margin.53,54 Any-where from 1.1 to 2.0 grams per kilogram can be ap-propriate for endurance athletes. The finalrecommendation for an individual should be basedon the following:� How many hours a week and how intensely is

the athlete training? The greater the number ofhours and the higher the intensity, the moreprotein an athlete will need. Recreational ath-letes should be encouraged to consume ap-proximately 1.1–1.4 grams of protein perkilogram of body weight, whereas elite ath-letes should aim for daily intakes closer to1.8–2.0 grams per kilogram.

� Is the athlete aiming to lose, maintain, or gainweight? Often endurance athletes are trying tolose weight in an attempt to increase theirspeed in sports such as long-distance running,duathlons, or cycling. When combining in-tense training and weight loss, protein needswill increase to the higher end of the spectrum(1.6–2.0 grams per kilogram). Athletes at-tempting to gain weight will also need more

protein daily in order to build new tissue(1.6–2.0 grams per kilogram). Those with thegoal of maintaining their weight will require amore moderate level of protein (1.1–1.5 gramsper kilogram).

� Is the athlete in a state of overtraining? Due tothe nature of endurance sports and the highervolume of training, endurance athletes aremore likely than other athletes to experiencethe effects of overtraining. Individuals who areovertrained feel fatigued, sore, and stale due tothe inability of muscles to completely recoverfrom long, intense training sessions. These in-dividuals can benefit from higher daily intakesof protein, aiding in the repair and recovery ofmuscles and tissues.

� Is the athlete consuming adequate carbohy-drates? For all endurance athletes, emphasisshould be placed on consuming enough carbo-hydrates, as well as adequate total calories, inorder to spare protein. Without adequate car-bohydrates and total energy, proteins are usedat a higher rate for energy production, thus in-creasing total daily requirements for dietaryprotein. However, if glycogen stores are high,carbohydrates are consumed during activity,and total calorie needs are met, protein can bespared and daily intake will remain moderate.The importance of carbohydrates for proteinsparing was demonstrated in a study con-ducted by Lemon and Mullin.29 The re-searchers revealed that protein accounted for4.4% of the energy needed to complete 1 hourof cycling at 60% VO2max in a glycogenloaded state versus 10.4% of the energy re-quired in a glycogen depleted state. The bot-tom line: Athletes should ensure carbohydrateintake is adequate while incorporating moder-ate amounts of protein on a daily basis.Refer to Table 12.3 for daily protein recommen-

dations for endurance athletes.

How can a daily meal plan be developed to meetthe protein needs of an endurance athlete?Dave is a competitive cross-country skier who trains3 hours a day, 6–7 days a week. Dave is 22 years oldand weighs 170 pounds. In order to develop an ex-ample meal plan for Dave, the first step is to deter-mine Dave’s daily energy needs and proteinrequirements. The second step is to show Dave howhe can put the recommendations into practice by de-veloping an example meal plan that provides ade-

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quate calories and protein. Following the energyrequirement equations listed in Table 12.1 and theprotein requirement calculations presented inTable 12.3, Dave’s needs can be calculated as follows:

1. Determine Dave’s calorie and protein needs:

a. For a 22-year-old male, the energy estima-tion equation is:

REE = (15.3 × BW) + 679

Dave’s body weight is 170 pounds or 77.2kilograms

REE = (15.3 × 77.2) + 679 = 1,860 calories × (activity factor of 1.6–2.4)

Total energy needs = 1,860 × (1.6–2.4) =∼3,000–4,500 calories per day

Dave’s average energy needs = (3,000 + 4,500) ÷ 2 = 3,750 calories per day

b. For an athlete exercising about 20 hours perweek, the protein needs are:

Protein needs = 1.7–2.0 grams or protein perkilogram of body weight

Protein needs = (1.7–2.0) × 77.2 kilograms = 131–154 grams of protein per day

Dave’s average protein needs = (131 + 154) ÷ 2 = 143 grams or protein per day

(15% of total calories)

2. Develop a meal plan to supply adequate caloriesand protein per day: Modifying the 4,000-calorieexample menu presented earlier in this chapter, ameal plan can be developed that meets Dave’s needsfor 3,000–4,500 calories per day as well as his re-quirement for 131–154 grams of protein each day.See Training Table 12.2 for an example meal plan thatmeets Dave’s total calories and protein requirements.

12.3 Daily Protein Recommendations for Endurance Athletes

Daily Protein Recommendation Activity Level (g protein/kg body weight)

Recreational athlete, 1.1–1.3exercising 10–12 hours per week

Competitive amateur 1.4–1.7athlete, training 12–20 hours per week

Elite athlete, training 1.7–2.0and competing 20+ hours a week

Training Table 12.2: Dave’s Meal Plan

Meal/Snack Food/Beverage Protein Content (grams)

Breakfast Smoothie:2 frozen bananas 22 cups skim milk 161 scoop protein powder 8.5

Snack 2 oranges 2Granola bar 4

Lunch 1 cup chili 223 oz roast beef sandwich 22.52 cups fruit salad 4.5

During workout 48 oz sports beverage 0

Postworkout snack 6 oz yogurt 81 cup dry cereal 2

Dinner 4 oz salmon 212 cups wild rice 133 cups salad with dressing 516 oz skim milk 16

Snack 11⁄2 cups frozen yogurt 101 cup frozen blueberries 0

Total Calories = 3,750 Total Protein = 156 grams16% of total calories

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What is the effect of consuming protein prior to endurance activities?As established earlier in this chapter, carbohydratesconsumed prior to endurance activities are criticalto optimal endurance performance. Is protein intakejust as important? The answer depends on when theprotein is consumed.

Protein-rich foods consumed in the preactivitymeal 2–4 hours prior to the initiation of enduranceexercise contributes to a feeling of satiation and aslowing of digestion, thus maintaining energy lev-els for a longer period of time. In addition, somestudies have suggested that protein consumption

prior to exercise is beneficial in regardsto the provision of branched chainamino acids (BCAAs). It has been sug-gested that consuming BCAAs beforeexercising might delay fatigue duringexercise via a mechanism involving theattenuation of central fatigue; however,the effect of consuming BCAAs im-mediately prior to exercise has so far

been shown to be small at best.12,34 Carbohydrate-rich foods should still take center stage in the pre-activity meal to supply the muscles with glucose forenergy, while protein assumes a supporting role. Con-suming too much protein before exercise can lead toa sluggish feeling due to a lack of carbohydrates aswell as dehydration due to increased urine produc-tion to flush out the byproduct of protein break-down, urea.

If protein-rich foods are consumed within anhour of endurance exercise, some researchers haveshown a negative impact on performance. Wileset al.50 reported a higher oxygen consumption rateduring various exercise intensities as well as an in-creased rating of perceived exertion when subjectsconsumed a moderate-to-high protein meal within1 hour of exercise. No negative effects were shownwhen the same quantity of protein was consumed3 hours prior to exercise. Therefore, it appears thatmoderate protein intake before exercise is beneficialif consumed with adequate quantities of carbohy-drates several hours prior to exercise. By consumingcarbohydrates, protein, and very small amounts offat before exercise, athletes can maintain a balanceand variety of foods within one meal, which is thegoal for all meals throughout training.

Should proteins be ingested during endurance activities?A significant amount of research has demonstratedthat amino acids are secreted from the muscle, oxi-

dized, and metabolized during exercise, thus im-plying their usage and importance during enduranceactivities.20,28 A majority of this research has focusedon the BCAAs—leucine, valine, and isoleucine.

The magnitude of BCAA usage is an importantconsideration for endurance athletes. It has been re-ported that a mere 2 hours of exercise at 55%VO2max oxidizes close to 90% of the daily totalrequirement for at least one of the BCAAs.14 It ap-pears that as endurance training intensity increases,the use of BCAAs also increases proportionately.44

These studies reveal that amino acids are used dur-ing endurance exercise and thus suggest a need forincreased overall daily protein intake for athletes.However, is it essential and beneficial to be con-suming protein during an activity versus before andafter training and competitions?

Some research has suggested that the consump-tion of protein during exercise may enhance en-durance performance. Several theories have arisen:� Usage of protein for energy production: Uti-

lization of BCAAs and provision of Krebs cy-cle intermediates have been suggested as thepathways for energy production and metabo-lism with protein ingestion.49

� Increased stimulation of insulin secretion: Acombination carbohydrate-protein supplementhas been found to stimulate insulin secretionafter prolonged exercise.46,52 This rise inplasma insulin has been hypothesized to leadto an increased glycogen synthesis, thus aidingin recovery from exercise. Recent researchershave suggested that it is possible that a similaraction may occur during exercise—that pro-tein (with carbohydrate) ingestion during exer-cise might increase insulin secretion and inturn spare muscle and liver glycogen usageduring exercise. Some studies have found anergogenic effect of adding protein to a carbo-hydrate supplement during exercise; however,they have failed to directly correlate insulinlevels or any other plasma or metabolic reasonfor the enhanced performance.55

� Suppression of central fatigue (see ):During endurance exercise there is a decreasein plasma BCAAs. At the same time, trypto-phan is unloaded from albumin at a higherrate into the plasma. BCAA and tryptophancompete for the same transporters across theblood-brain barrier; therefore, when BCAAlevels decrease, a higher percentage of trypto-phan can attach to the transporters, increasing

Figure 12.3

branched chain aminoacids (BCAA) A group ofamino acids whosecarbon side chain,unlike other aminoacids, is branched. Thebranched-chain aminoacids include leucine,isoleucine, and valine.

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the brain’s uptake of tryptophan. Tryptophanconverts into serotonin, which has a relax-ation effect, ultimately causing an athlete tofeel fatigued and eventually cease exercising.11

Some researchers have suggested that the in-gestion of BCAAs during exercise will main-tain the plasma concentration and thus delayfatigue and enhance endurance performance.This theory has been supported in some stud-ies and refuted in others.2,3,33,45 More researchis needed to draw definitive conclusions.These theories and relevant research are still in

their infancy and require more studies to clarify theactions of ingested proteins and amino acids dur-

ing exercise and their associated mech-anisms and effects on performance.

Regardless of actual performancebenefits from ingesting amino acids,foods and drinks containing protein canbe beneficial to consume during en-durance activities, especially ultra-endurance events, from a practicalstandpoint. Items containing some pro-tein in general will be less sweet butmore salty than the typical endurancesport fare. When a training session orcompetition continues for 4–24 hours,flavor fatigue is of great concern becausewhen an athlete stops ingesting calories,energy levels will soon plummet. Manysports nutrition products have a sweetflavor, and therefore salty foods are gen-erally a welcomed change of taste. Con-versely, if too much protein is consumed,gastric emptying can be delayed, whichcan cause stomach cramping and de-layed absorption of nutrients. Somepractical ideas for items that have mod-erate amounts of protein, are easily di-gestible, and are compact for carryingduring activities such as hiking, day-long bike trips, or adventure races in-clude energy bars, sesame sticks, peanutbutter sandwiches, peanut butter crack-ers, meat jerky, trail mix, and mixednuts.

Is protein needed for recovery from endurance exercise?Although not as critical as carbohydrateconsumption, protein consumption af-ter endurance exercise aids in the re-

covery process. Several proposed roles of proteinafter endurance exercise include enhancing the in-sulin response to accelerate glycogen synthesis andrebuilding damaged muscle tissue.

Research began with the investigation and dis-covery that protein added to a carbohydrate sup-plement can enhance the insulin response, suggestinga hastened delivery of nutrients into the cells ver-sus carbohydrates alone.38,42 Further studies thenexplored whether the increase in insulin levels cor-related with greater amounts of glycogen severalhours postexercise. A study completed by Zawadzkiet al.,52 mentioned in Chapter 5, is often cited whenjustifying the need for protein after exercise to





5-HT 5-HT





































Suppression of central fatigue. A decrease in branched chain aminoacids (BCAA) levels can cause an increase in the brain’s uptake of tryptophan (TRP).Tryptophan converts into serotonin (5-HT), which has a relaxation effect, resulting infatigue and ultimately the cessation of exercise. A = albumin, FA = Fatty acid, f-TRP = Free tryptophan.

Figure 12.3

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maximize glycogen levels. The researchers reportedthat after several hours of cycling, the athletes whoconsumed a combination carbohydrate and pro-tein supplement had higher levels of glycogen thanthe cyclists who consumed only carbohydrates. How-ever, it should be noted that the combination sup-plement had more total calories than thecarbohydrate-only supplement, which may have con-tributed to the enhancement, not necessarily the pair-ing of protein and carbohydrates. Regardless,protein-rich foods consumed after exercise will pro-vide a unique profile of nutrients as well as supplyamino acids needed for muscle repair.

Researchers at Indiana University (Karp et al.61)studied chocolate milk compared to traditional car-bohydrate replacement beverages as a recovery aidfollowing exhaustive exercise in nine endurance-trained cyclists. Subjects performed an interval work-out to deplete muscle glycogen, followed by 4 hoursof recovery and then an endurance performance trialto exhaustion. Subjects consumed an equivalentamount of carbohydrates (1 g/kg body weight) froma traditional ready-to-drink carbohydrate replace-ment drink or chocolate milk immediately after thedepletion exercise and again 2 hours later. Resultsshowed that consumption of chocolate milk after ex-ercise was equal to or better than traditional car-bohydrate drinks in time to exhaustion and totalwork for the endurance trial to exhaustion. More re-search is needed to determine if the combined pro-tein and carbohydrates in chocolate milk, instead ofcarbohydrates alone, helped improve these athletes’performance during the endurance trial phase of thestudy. Chocolate milk is highly palatable and inex-pensive compared to many ready-to-drink sport sup-plements. This research could prove valuable forathletes to practically and inexpensively apply re-covery nutrition to their daily diet.

The repetitive nature of endurance sports has ledto the recommendation to consume protein after ex-ercise to repair muscle tissue. Especially after repet-itive eccentric movements, such as running, musclesmay experience microtrauma requiring amino acidsas building blocks to repair the damage. Some re-search suggests that the microtrauma to the musclecells contributes to muscle soreness after exercise.Therefore, if protein-rich foods consumed immedi-ately after endurance exercise supply amino acidsfor hungry muscles, muscle soreness may bedecreased.

Similar to carbohydrate foods, protein-rich foodsshould be consumed within 15–30 minutes post-

exercise to maximize the delivery of nutrients tothe muscles. Approximately 6–20 grams of proteinimmediately following endurance exercise appearsto be sufficient to initiate the recovery process. Con-tinuing to consume protein in subsequent mealsthroughout the day will supply the total daily re-quirements of protein for an athlete and thus aid inthe continuous rebuilding and repair of tissues be-fore the next endurance exercise bout.

Should endurance athletes eat more fats to meet their energy needs?

Because the body relies on fats for energy and theenergy requirements for endurance athletes are high,one might be foolishly misled into thinking that fatintake should be of prime importance in the diet ofendurance athletes. Numerous studies have demon-strated that endurance training does indeed causemetabolic adaptations that enables the body to relymore heavily on fat metabolism for energy duringexercise (see Figure 3.7 in Chapter 3). This is animportant adaptation because it decreases the drainon the body’s somewhat limited carbohydrate re-serves ( ). However, the onset of fatigueduring endurance training and competition is notcaused by exhausting the body’s fat reserves; in mostcases it is due to depletion of carbohydrate stores.Therefore, increasing the percentage of calories fromfats in the diet does little to enhance performance be-cause it is the availability of carbohydrates that ul-timately limits the metabolizing of fats in relation todelaying the onset of fatigue.

However, some researchers have suggested thata high-fat diet, either consumed for a single mealor for several weeks, may actually be advantageousto endurance athletes. The theory is that because fatusage during exercise is due in part to the concen-tration of free fatty acids in the plasma, if blood lev-els can be increased, more fats will be used for energy,sparing carbohydrates and possibly enhancing en-durance performance. Studies have investigated theergogenic benefit of short-term and long-term high-fat diets to determine whether increasing the fat con-tent of one meal or the daily diet can cause the bodyto adjust and adapt to become a higher fat-burningmachine.

Several methodical strategies have been used inshort-term high-fat studies. Most of the researchshowing a positive result from a single high-fat mealhas included the infusion of heparin. Heparin stim-ulates lipoprotein lipase activity, which in turn in-

Figure 12.4

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creases the plasma levels of free fatty acids in theblood. Because the infusion of heparin before en-durance activities is not considered a sound medicalpractice, these studies provide little relevant infor-mation to the practical world of endurance sports.In the studies that involve strictly high-fat meals andsubsequent tests of endurance (without heparin in-jections), most show no benefit over a high-

carbohydrate meal.36,39

The effect of fat loading (i.e., con-suming high levels of fat in the diet) onendurance performance has been eval-uated in studies of high-fat diets con-sumed for 3–5 days prior to exercise.Studies have compared the effect of a

high-fat diet (more than 74% of total calories) ver-sus a high-carbohydrate diet (more than 77% oftotal calories) on performance tests to exhaustion.Results have consistently shown that high-fat dietshave a negative impact on endurance perfor-mance.15,18,27 At this time, fat loading cannot be rec-ommended as a method of improving performancein endurance activities.

Another set of studies has focused on the effecton endurance performance of a high-fat diet con-sumed for 1–4 weeks. It appears that individuals con-suming a high-fat diet for this moderate length oftime can adapt to using more fat for fuel, and thusincrease time to exhaustion in endurance tests. Lam-bert et al.28 studied five endurance cyclists who con-sumed either a high-fat diet (76% of total calories)or a high-carbohydrate diet (74% of total calories).After 2 weeks on the diet, the subjects consumed anormal diet for 2 weeks and then consumed the op-posite diet plan for 2 weeks. After each 2-week ex-perimental set, the cyclists performed a Wingatepower test, a high-intensity exhaustion test (90% ofVO2max), and a moderate-intensity exhaustion test,cycling at 60% of VO2max. No difference was notedon the power test or the high-intensity test. How-ever, the cyclists performed better in the moderate-intensity cycle test (increased endurance) whenconsuming the high-fat diet. The authors attributedthe benefit to a lower respiratory exchange ratio,meaning the individuals were relying more on fatsfor energy than carbohydrates. However, it shouldbe noted that the endurance test was performed af-ter two other intense physical tests, with little restbetween tests, which can impact endurance perfor-mance and thus make the interpretation of theseresults difficult. Other studies have suggested a ben-efit from a moderate- or high-fat diet, but with vary-

ing levels of fat intake, the use of trained and un-trained subjects, and different testing/diet protocols,comparisons are difficult and drawing conclusionshas been challenging.23,48

Finally, long-term studies (>7 weeks) on the ef-fects of a high-fat diet on endurance performancehave failed to show an ergogenic benefit.22 In addi-tion to inconsistent results from short-term to long-term high-fat consumption, high-fat diets shouldbe evaluated based on the following:� Fat takes longer to digest, and therefore high-

fat meals put the athlete at higher risk for gas-trointestinal issues during exercise.

� High-fat diets can lead to flavor fatigue rela-tively quickly, causing an athlete to stray fromthe prescribed diet, thus making a long-termplan impractical.

� High-fat diets have been shown to negativelyaffect cardiovascular health long term, andtherefore are not generally recommended.Currently, the available research does not sup-

port a widespread recommendation for athletes toconsume a high-fat meal prior to endurance exerciseor to follow a high-fat diet plan. More research isneeded to fully understand the effects of high-fatmeals on endurance athletes and the mechanismsinvolved. Dietary fat provides additional caloriesnecessary for athletes with high daily energy ex-penditures. Foods that contain fat also provide vi-tamins and minerals that are essential to optimalsport performance in endurance events. Enduranceathletes can consume moderate amounts of fat, if de-sired, so long as dietary fat does not replace the car-bohydrates and protein necessary for success inendurance exercise.

How are daily fat needs calculated for enduranceathletes?For endurance athletes, fat requirements are gener-ally calculated after determining carbohydrate andprotein needs. Carbohydrates are the main fuel inthe body for endurance sports and protein is criticalfor repairing muscle tissue after long-duration ac-tivities, especially weight-bearing sports. Therefore,both macronutrients take precedence over fat. How-ever, the importance of dietary fat should not bedownplayed—fatty acids are critical for meeting to-tal energy needs, obtaining essential fatty acids, andabsorbing fat-soluble vitamins from foods andbeverages.

One of the main functions of fat in the enduranceathlete’s diet is to provide a concentrated source of

fat loading The dietarypractice of eating a diethigh in fats (i.e., > 60%of total daily calories)3 to 5 days prior tocompetition.

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energy. For athletes training 3–6 hours or more aday, energy needs can climb into the 4,000–6,000calorie range. Consuming enough food to meet theseenergy needs can be challenging, especially if an ath-lete is aiming to meet these needs with predominantlycarbohydrates and protein. Meeting high energyneeds with mainly carbohydrate- and protein-richfoods will require an athlete to eat very large vol-umes of food that can cause gastrointestinal dis-comfort. The large volume of food may also bechallenging from a schedule standpoint, requiringan athlete to eat 6+ meals and snacks a day; eatingthat frequently becomes difficult when 3–6+ hoursa day are spent exercising. Conversely, fat-rich foodsare calorie-dense, allowing an athlete to consumemore calories with less food and without feeling toofull or bloated.

As with any athlete, moderate amounts of fatmust be consumed on a daily basis in order to ob-tain the essential fatty acids provided in food. En-durance athletes—especially those trying to loseweight or body fat—often become too focused oncarbohydrates and lean protein sources, while at-tempting to minimize or eliminate fat intake. Ath-letes need to remember that fat is a healthy part ofa daily diet. Essential fatty acids provide energy, helpto produce hormones in the body, surround all nervescontributing to proper nerve function, and aid in theabsorption of fat-soluble vitamins and antioxidants.

Fat-soluble vitamins—vitamins A, D, E, and K—are all critical nutrients for an endurance athlete.Vitamins A and E are classified as antioxidant vita-mins, helping to neutralize oxidative damage that oc-curs during exercise. Vitamin D works closely withcalcium to provide structure and strength to bones—essential for weight-bearing activities and the pre-vention of stress fractures. Vitamin K has the roleof helping blood to clot. Cuts and gashes can occurduring some endurance sports, such as mountain bik-ing or adventure racing, and an athlete will be thank-ful that their blood can clot properly, ceasing the flowof blood and allowing the injury to heal. All of thesevitamins cannot be absorbed to their full capacity ifnot consumed with a small amount of dietary fat.

In summary, fat is important in an endurance ath-lete’s diet, but only moderate amounts are needed. Ifcarbohydrate needs are calculated at 50%–65% of to-tal calories, and protein needs fall between 12% and20%, then the remaining calories should be contributedby fat—approximately 20%–35% of total calories.Most often, fat needs for endurance athletes will becalculated at the lower end of this range. However, if

calorie needs are very high, fat intake at 30%–35% oftotal calories will ensure adequate total calories, a feel-ing of satiety, and a decrease in the total volume offood that needs to be consumed in one day.

For example, Brooke is a cyclist, riding 150–200miles a week. She is 30 years old, is 5′8″, weighs 132pounds, and wants to maintain her weight. In or-der to calculate her fat needs:

1. Determine her total energy needs:

REE = (14.7 × 60 kg) + 496 = 1,378 × (1.6–2.4) = ∼2,200–3,300

Brooke’s average calorie needs = 2,750 calories per day

2. Determine her carbohydrate (CHO) needs:

5–10 grams carbohydrates × kilograms of bodyweight = 5–10 g × 60 kg = 300–600 grams

Brooke’s average carbohydrate needs = 450 gramsof carbohydrates per day (65% of total calories)

3. Determine her protein needs:

Training 12–20 hours per week = 1.4–1.7 grams of protein per kilogram of body weight (1.4–1.7)

× 60 kg = 84–102 grams of protein

Brooke’s average protein needs = 93 grams of protein per day (14% of total calories)

4. Determine her fat needs:

Remaining calories based on percentage = 100 – 65 (CHO) – 14 (protein) = 21% of total

calories from fat 21% of 2,750 = 577.5 calories ÷ 9 kcal/gram of fat

= ∼64 grams of fat per day

In summary, for endurance athletes, calculate to-tal energy needs first. Then, determine carbohydrateand protein requirements in total grams as well asa percentage of total calories. The remaining percentageof calories should come from fat. Double-check thecalculations to ensure that fat intake does not fall be-low 20% of total calories, to prevent fatty acid defi-ciencies, and does not exceed 30%–35%, for hearthealth and overall dietary balance. The ranges for car-bohydrates, protein, and fat provide a wide spectrumof appropriate options in order to develop a nutri-tion plan that incorporates balance, variety, and mod-eration while simultaneously providing enough fuelfor an athlete to remain energetic, fresh, and recover-ing well from hard workouts and competitions.

Should fats be eaten while performing enduranceactivities?During low-to-moderate-intensity activities, a ma-jority of energy is derived from fatty acids in the

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blood. Because fats are such an important fuel source,it would seem logical that consuming fats (long-chaintriglycerides) while competing in endurance sportswould be a good practice. However, other factorsmust be taken into consideration regarding fat in-take during competition. First, depleting the body’sfat stores, even on the leanest of individuals, is nota likely scenario and thus not an energetic cause offatigue. Additionally, fatty foods are slow to digest,delay gastric emptying, and may cause gastroin-testinal cramping and diarrhea—none of which willenhance performance. Despite the negative effectsof consuming dietary fats during endurance exercise,

some researchers have suggested thatingestion of medium-chain triglycerides(MCTs) may be beneficial by sparingendogenous carbohydrate stores andenhancing endurance performance.MCT supplements marketed to en-

durance athletes have suggested benefits such as in-creased energy levels, enhanced endurance, increasedfat metabolism, and lower body fat levels. Althoughthese claims sound appealing, research has not beenable to consistently support these statements.

An early focus of research was centered on thefact that MCTs can be oxidized as rapidly as ex-ogenous glucose. The theory derived from this factwas that MCTs could potentially spare the usageof muscle glycogen as well as exogenous glucose dur-ing endurance exercise, thus delaying fatigue. Twodifferent studies13,25 from the early 1980s with sim-ilar methodology revealed similar results. Both stud-

ies compared the effects of consuming 25–30 gramsof MCTs or 50+ grams of carbohydrates before1 hour of exercise at 60%–70% VO2max on sub-strate utilization and glycogen sparing. The amountof carbohydrates and fat used during the hour of ex-ercise was virtually identical across experimentalgroups and glycogen stores were not spared.

The next step was for researchers to investigatethe effects of larger quantities of MCTs to determineif earlier studies did not find a benefit due to lowdosages. It should be noted that earlier studies doc-umented preliminary findings of gastrointestinal in-tolerances of MCTs at doses higher than 50–60grams.25 Despite this information, future studies werecompleted with doses upwards of 85 grams of MCTs.The first study performed by Van Zyl and associ-ates47 studied the effects of glucose, MCT, or glu-cose plus MCT ingestion during cycling. Sixendurance-trained cyclists performed a 2-hour boutof cycling at 60% VO2max, followed by a 40-kilometer time trial. While cycling on separate oc-casions, the subjects consumed one of three beveragesin random order: 10% glucose, 4.3% MCT, or 10%glucose + 4.3% MCT solution. The MCT-only bev-erage negatively affected the time trial performanceby 5.3 minutes, while the combination beverage im-proved performance by 1.7 minutes compared toglucose alone. Unfortunately, muscle glycogen lev-els were not directly measured in this study, and there-fore the glycogen sparing theory of MCTs could notbe confirmed.

A follow-up study was performed by Jeukendrupand associates,26 once again testing cyclists con-suming glucose only, MCT only, or a combinationbeverage. Several differences in experimental designwere implemented as compared to the Van Zylstudy47:

1. A 5% MCT solution was used instead of a 4.3%solution (the 10% glucose solution remained thesame).

2. A placebo group was included.3. The time trial after the 2 hours of cycling at 60%

VO2max involved the maximum amount of workproduced in 15 minutes versus the time to com-plete a 40-kilometer distance.

4. Carbohydrate and protein utilization during ex-ercise was measured.The authors found no difference in performance

amongst the placebo, glucose, and glucose + MCTtrials. However, they did find a 17%–18% decreasein performance when cyclists consumed the MCT-only beverage. The MCT beverage also did not alter

Endurance training causes metabolic adaptationsthat enable the body to rely more heavily on fat metabolism forenergy during exercise. This is an important adaptation becauseit decreases the drain on the body’s somewhat limitedcarbohydrate reserves.

Figure 12.4

medium-chaintriglycerides (MCT)A glycerol molecule withthree medium-chainfatty acids attached.

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carbohydrate or protein utilization during exercise,thus not sparing glycogen stores. It was documentedthat several subjects vomited during the MCT tri-als and others suffered from diarrhea.

In conclusion, long-chain triglycerides are notrecommended for consumption during endurancesports. Small amounts may be consumed during ultra-endurance events lasting more than 4–6 hours with-out consequence; however, the amount should remainminute, with the focus placed primarily on carbo-hydrates and secondarily on protein. Some examplesof fat-containing foods that may be tolerated duringlong-duration activities include peanut butter sand-wiches, trail mixes, and sesame sticks. Intake of thesefoods should be tested during training and incor-porated based on individual tolerance. Although afew researchers suggest a benefit of consuming smallamounts of MCTs during endurance activities, theresults have not consistently shown improvementsin endurance performance. Although greater amountsmay have a more significant impact on substrate uti-lization, large quantities of MCTs have also beenshown to increase gastrointestinal distress. At thistime, a recommendation cannot be made for en-durance athletes to consume MCTs prior to and dur-ing training or competition.

Is fat needed for recovery from endurance exercise?Unlike carbohydrates and protein, it is not essen-tial to replace fat used during endurance exercise byconsuming certain quantities or types of fat imme-diately following training or competition. The body’sstores of fat are so great that they will not be depletedin an exercise session, even after prolonged enduranceevents. Because ingesting carbohydrates and proteinis the main priority after endurance training, al-lowing the replacement, restoration, and replenish-ment of muscles, fat should be kept to a minimum.Fat causes the stomach to empty more slowly thando carbohydrates and protein, which could poten-tially delay the delivery of nutrients to the musclesin a timely fashion. However, fats add flavor to foodsand create a sense of satiety, and therefore can be in-cluded in small amounts in the postexercise mealor snack.

Are vitamin/mineral needs different for endurance athletes?

Endurance athletes need higher levels of various nu-trients, including some vitamins and minerals, ascompared to their sedentary counterparts. But are

specific vitamins and minerals of greater importanceto endurance athletes versus team sport orstrength/power athletes? Although all vitamins andminerals are needed in adequate amounts for properhealth and bodily functioning, a handful of vitaminsand minerals are in the spotlight for endurance ath-letes: B vitamins, iron, calcium, vitamin C, vitamin E,sodium, and potassium.

Why are the B vitamins important for enduranceathletes?B vitamins, specifically thiamin, riboflavin, andniacin, are involved in energy production pathwaysand thus are required in higher amounts for en-durance athletes.57 Thiamin plays a role in the con-version and utilization of glycogen for energy andthe catabolism of branched-chain amino acids. Ri-boflavin is highly involved in the production of en-ergy from carbohydrates, proteins, and fats for bothhealth and performance. Niacin is a component oftwo coenzymes: nicotinamide adenine dinucleotide(NAD) and nicotinamide adenine dinucleotide phos-phate (NADP). These coenzymes are involved inoxidation-reduction reactions required for the pro-gression of metabolic pathways toward the synthe-sis of fatty acids and glycogen.

Increased intake of these B vitamins is importanton a daily basis, but is not necessarily required dur-ing exercise. The key is for endurance athletes to con-sume thiamin-, riboflavin-, and niacin-rich foodsthroughout the day, at meals and snacks. See Table 12.4for examples of thiamin-, riboflavin-, and niacin-richfoods.

Why is iron important for endurance athletes?Iron is best known for aiding in the formation ofcompounds essential for transporting and utilizingoxygen (myoglobin and hemoglobin), and is there-fore critical for aerobic activities and endurance train-ing. Iron deficiency is one of the most commonnutrient deficiencies in the United States and there-fore deserves special mention to and the attention ofendurance athletes. Due to the nature of endurancesports, athletes experience an increasedloss of iron. Hematuria, or the pres-ence of hemoglobin or myoglobin inthe urine, is due to a breakdown of redblood cells. The breakdown of redblood cells, also known as hemolysis,results in the release of hemoglobin andultimately its elimination from the bodyvia urine. Hemolysis, which is believed

hematuria The presenceof hemoglobin ormyoglobin in the urine.Hematuria is anindicator of hemolysis.

hemolysis Thebreakdown of red bloodcells.

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to be at least partially due to repeated impact, is com-mon in distance runners.58 Nonimpact endurancesport athletes, such as rowers or cyclists, can also ex-perience hemolysis due to loss from the intestinalwall, in urine or feces, due to an irritation caused byequipment and body friction, oxidative stress causedby the formation of free radicals, and/or the con-sumption of nonsteroidal anti-inflammatory drugs.58,59

Iron can also be lost through sweat. Endurance ath-letes lose a lot of sweat on a daily basis, further jus-tifying an increased emphasis on adequate dailyintake of iron.

Endurance athletes should focus on consumingiron-rich foods on a daily basis at meals and snacks.Similar to B vitamins, it is not necessary to con-sume iron-rich foods during activities. See Table 12.4for examples of iron-rich foods.

Why is calcium important for endurance athletes?Calcium is widely recognized as a bone strengthen-ing mineral. However, calcium’s role in enduranceperformance extends beyond the skeleton. Calciumhelps to produce fibrin, the protein responsible forthe structure of blood clots. It is required for propernerve function, releasing neurotransmitters that fa-cilitate the perpetuation and activation of nerve sig-nals. Calcium is pumped into and out of muscle cellsto initiate both muscle contraction and relaxation insmooth muscle, skeletal muscle, and the heart. Thesefunctions are all essential for endurance athletes tomaintain the intensity and duration of training andcompetition. During exercise, heart rate, muscle con-traction and relaxation, and nerve impulse activityare all increased at incredible rates for sustained

12.4 Key Vitamins and Minerals for Endurance Athletes

Importance Related to Endurance Sports Food Sources Critical Consumption Time Frame

VitaminsThiamin Energy production

Riboflavin Energy production

Niacin Energy production

Vitamin C Antioxidant

Vitamin E Antioxidant

MineralsIron Oxygen-carrying compounds

and energy-producing enzymes

Calcium Bone strength

Sodium Electrolytes lost in sweat

Potassium Electrolytes lost in sweat

Fortified and whole grains, legumes, wheat germ, nuts, pork

Milk, yogurt, bread and cereal products,mushrooms, cottage cheese, and eggs

Beef, poultry, fish, legumes, liver, seafood,fortified and whole grain products,mushrooms

Citrus fruits, berries, melon, tomatoes, greenleafy vegetables, bananas, sweet potatoes

Nuts, seeds, wheat germ, fortified cereals,strawberries

Beef, poultry, fish, soy products, driedfruits, legumes, whole grains, fortifiedcereals, green leafy vegetables

Milk, yogurt, cottage cheese, hard cheese(and nondairy alternatives), fortifiedfoods, and juices

Table salt, condiments, canned foods,processed foods, fast foods, smokedmeats, salted snack foods, soups

Fruits, vegetables, coffee, tea, milk, andmeat

Daily meals and snacks

Daily meals and snacks

Daily meals and snacks

Daily meals and snacks as well as afterintense, long training sessions

Daily meals and snacks as well as afterintense, long training sessions

Daily meals and snacks

Daily meals and snacks

Daily meals and snacks, during workoutslasting longer than 4 hours, after exer-cise to replenish sodium losses

Daily meals and snacks, small amountsduring exercise, after exercise to re-plenish potassium losses

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periods of time. Calcium also activates several en-zymes that affect the synthesis and breakdown ofmuscle and liver glycogen, which is the main en-ergy source during endurance exercise. Although crit-ical in many ways for peak performance, manyathletes are consuming suboptimal amounts of cal-cium on a daily basis. By striving for three to fourservings of milk/alternatives, or other calcium-richsources every day, athletes can meet their calciumneeds. Calcium intake is not required during train-ing sessions or competitions. Calcium stored withinthe body and the small amounts consumed in pre-exercise meals will provide the calcium needed dur-ing activity for proper nerve function and musclecontraction. See Table 12.4 for examples of calcium-rich foods.

Why are vitamins C and E important for enduranceathletes?Vitamins C and E have recently been acknowledgedas potent antioxidants, helping to combat the ox-idative damage that can occur during intense en-durance exercise. Some research has shown thatvitamins C and E actually work in concert with oneanother, enhancing each other’s antioxidantproperties.

Megadose supplements of vitamins C and E areoften marketed to endurance athletes, touting en-hanced recovery from intense workouts. Althoughthese vitamins can make an impact on the recoveryprocess, there is a safe and acceptable limit to dailyintake. Vitamin C intake of 250–500 mg per day isabove the RDA of 90 mg for males and 75 mg forfemales, yet far below the tolerable upper limit (UL)of 2,000 mg daily for adults.62 Intake of 250–500 mgwill assure that endurance athletes are meeting min-imum needs and also possible additional antioxidantneeds from the added stress of physical activity. Thislevel is easily obtained through a balanced diet in-cluding plenty of fruits and vegetables and meetingdaily energy needs. Supplementation of vitamin Ehas become quite popular with endurance athletesdue to recent studies touting its antioxidant abili-ties.63 This research is conflicting (see Chapter 6);a prudent approach to vitamin E intake is to re-main below the UL of 1,000 mg (1,500 IU) daily. En-durance athletes who may not meet daily energyneeds or are restricting dietary intake for weight con-trol may require vitamin E supplementation. Becauselarge amounts of vitamin E are rarely toxic, sup-plementation at far higher than the 15 mg (23 IU)RDA is not a concern for most endurance athletes.

However, it is also not clear if and at what level ofsupplementation vitamin E might benefit enduranceathletes’ performance. Combined dietary and sup-plemental vitamin E intakes of 100–270 mg daily (orapproximately 150–400 IU) is appropriate and willassure adequate intake without concern for negativeside effects. See Table 12.4 for examples of vitamin C-and vitamin E-rich foods.

Why are sodium and potassium important for endurance athletes?Sodium and potassium are crowned as heroes fortheir critical roles during endurance exercise.Sodium, one of the extracellular elec-trolytes, acts in conjunction withpotassium, one of the intracellularelectrolytes, to maintain proper fluidbalance throughout the body duringlong-duration exercise. The inter-change and flow of these electrolytesinto and out of cells is responsible forthe transmission of nerve impulses andmuscle contractions. Sodium andpotassium are both lost in sweat; how-ever, sodium losses are of greater mag-nitude and significance. If sodium lossduring exercise is excessive, withoutreplacement, a life-threatening condition called hy-ponatremia can result. Sodium also aids in the ab-sorption of glucose, which makes it a keycomponent to any sports beverage.

Most Americans, including athletes, consumeplenty of sodium on a daily basis. For athletes par-ticipating in ultra-endurance events, adding a littlemore sodium to meals and snacks in the days lead-ing up to an event can help to “stockpile” a little ex-tra sodium for race day. Sodium consumption duringendurance training and competitive events is im-portant for health and performance. Refer to the fol-lowing section, “Why are fluids critical to enduranceperformance?” for more information on calculatingsodium needs for athletes during endurance eventsas well as guidelines for developing a nutrition planthat includes sports beverages, foods, and salt sup-plements. The replacement of salt after enduranceexercise is easily accomplished by consuming saltyfoods and beverages.

On the other hand, most Americans, includingathletes, are not doing a good job of consumingenough potassium on a daily basis. This suboptimalintake has been attributed to a low consumption offruits, vegetables, and low-fat dairy products. En-

electrolytes Positively ornegatively charged ionsfound throughout thebody. The body usesthe electrolytes toestablish ionicallycharged gradientsacross membranes inexcitable tissues such asmuscle and nerves sothat they can generateelectrical activity. Themost well-knownelectrolytes are sodium(Na+), potassium (K+),and chloride (Cl–).

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durance athletes should be encouraged to eat moreof these foods every day. During exercise, potassiumcan be obtained from sports beverages, as well ascommonly consumed endurance fare such as bananasand oranges. See Table 12.4 and for ex-amples of sodium- and potassium-rich foods.

Why are fluids critical to enduranceperformance?

As discussed in Chapter 8, 60% of our body weightis water. Fluid intake and maintenance of body wa-ter levels are critical to the endurance athlete for sev-eral reasons, in particular for the regulation of bodytemperature and maintenance of blood plasma vol-ume. During exercise, the body’s primary means ofcooling itself is through the evaporation of sweat.Failure to adequately rehydrate during and aftertraining leads to dehydration, which in turn resultsin elevated body temperatures during exercise. Ele-vated body temperatures cause an increased strainon the cardiovascular system, which is already a weaklink in the aerobic power of most athletes, and leadsto overheating of the body, which has negative andsometimes deadly consequences.

Blood plasma volume is one of the most impor-tant determinants of aerobic capacity because thecardiovascular system’s ability to deliver oxygen is

Figure 12.5

rate limiting in regards to exercise intensity. The moreblood that can be delivered to working muscles,the faster oxygen can be used for the aerobic pro-duction of ATP. The direct consequence of this is thatthe athlete can perform or maintain a faster race pacewithout the build-up of lactic acid, which ultimatelycan cause fatigue. If an athlete becomes dehydrated,the blood plasma volume decreases to support sweatformation for evaporative cooling purposes. The re-sulting decrease in blood plasma volume leads to adecrease in the cardiac output of the heart, whichin turn decreases delivery of oxygen to the workingmuscles and slows aerobic performance. Obviously,maintenance of hydration is of utmost importanceto the endurance athlete because of the direct nega-tive consequences inadequate fluid intake can haveon performance.

How are daily fluid needs calculated for enduranceathletes?An endurance athlete cannot rely on becoming well-hydrated during activity by drinking copious amountsof fluids if he or she is not well-hydrated at the on-set of exercise. In order to be well-hydrated at theonset of exercise, endurance athletes should followthe daily hydration guidelines stated in Chapter 8 ofthis book. As a reminder, the AI of water for menand women over age 19 is 3.7 liters and 2.7 litersof water per day, respectively. Basic fluid needs canalso be estimated based on an athlete’s total dailycalorie needs (see Chapter 8 for the estimation cal-culation). Remember, fluid losses during exercise arein addition to daily fluid recommendations. Due tothe frequency and duration of en-durance athletes’ training and compe-tition sessions, maintaining euhydration(i.e., a positive fluid balance) is of ut-most importance and should be a di-etary focus every day.

How are fluid and electrolyteneeds during enduranceactivities determined?Maintaining euhydration duringendurance activities is depend-ent on making accurate estima-tions of individual sweat ratesand electrolyte losses, practicingthe consumption of the estimatedamounts of fluid while exercis-ing, and overcoming any logisti-cal barriers to fluid availability.

Choose foods with potassium and sodium afterlong exercise bouts to replenish these lost electrolytes.

Figure 12.5

euhydration A state ofpositive fluid balance inwhich more fluids arebeing ingested thanbeing lost.

gaining the performance edge

Endurance athletes shouldmake it a habit to carry awater bottle throughout theday. The physical reminderof holding a water bottleand the immediateavailability of water will helpathletes meet their dailyfluid needs.

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How do endurance athletes determine theirindividual fluid needs?If left to their own devices, endurance athletes willtypically not drink enough fluid during exercise tomaintain euhydration.19,32 In a study conductedby Iuliano et al.,24 female and male junior elite triath-letes performed a simulated duathlon event con-sisting of either a 2-km run, 12-km bike ride, and4-km run or a 1-km run, 8-km bike ride, and 2-kmrun based on age. All subjects were allowed to drinkad lib of their chosen beverage during all three seg-ments of the simulated duathlon. All groups dranksuboptimally, as revealed by a loss of body mass,both in absolute and relative terms. Many enduranceathletes are not aware of how much fluid they arelosing during exercise; therefore, the first step in pro-moting an athlete’s awareness is to perform a sweattrial and then to practice their “ideal” fluid con-sumption frequently in training sessions. To reviewthe sweat trial calculations presented in Chapter 8:

1. Determine body weight (BW) lost duringexercise:

BW before exercise – BW after exercise = pounds of water weight loss

2. Determine the fluid equivalent, in ounces, of thetotal weight lost during exercise:

Pounds of water weight lost during exercise × 16–24 ounces = number of ounces of additionalfluid that should have been consumed to maintain

fluid balance during the exercise session

3. Determine the actual fluid needs of the athleteduring an identical workout:

Ounces of fluid consumed + ounces of additional fluid needed to establish fluid balance

= total fluid needs

4. Determine the number of fluid ounces neededper hour of exercise:

For practical purposes, total fluid needs ÷ durationof the sweat trial, in hours = number of fluid

ounces needed per hour of exercise

For example, Jack is preparing for an ultra-endurance bike ride called the RAIN ride (RideAcross INdiana), which consists of riding 162 milesacross the state of Indiana in one day. As part ofhis training, he participates in a 110-mile group bikeride. The ride takes 7.5 hours. During this time hedrinks 224 fluid ounces of a sports drink. By the endof his workout, he had lost 8 pounds of body weight.What is the ideal amount of fluid he should be con-suming per hour?

Using the steps stated above:1. His body weight loss during the workout was

8 pounds.2. The fluid equivalent of his loss was 128–192

ounces (8 × 16–24 oz).3. His total fluid needs for the 7.5 hours of cy-

cling are 352–416 ounces (224 oz + 128–192 oz).4. Jack needs 47–55 ounces of fluid per hour to

match his sweat losses (352–416 ÷ 7.5).For practical purposes, 47–55 ounces of fluid per

hour is equivalent to 2.3–2.75 bottles per hour (as-suming 20-oz bottles). For Jack, it would be in hisbest interest to install at least four wa-ter bottle holders on his bike sohe could carry enough fluid forseveral hours of riding. BecauseJack was only drinking about 30 ounces per hour during the110-mile training ride (224 oz ÷7.5 hours = 29.8 oz/hour), he willneed to practice drinking160%–180% more fluid perhour before participating in theRAIN ride. A change in drinkingbehavior of this magnitudeshould be incorporated over timeand not made overnight, to allowthe body to adjust.

It is ideal for an athlete to consume mainly—ifnot solely—sports beverages during endurance ac-tivities lasting longer than an hour. A sports bever-age delivers not only fluids, but also carbohydrates,sodium, and other electrolytes to the body. Gener-ally, liquids or semi-solid foods consumed whileexercising settle better than solid food. Therefore, ifcalories, carbohydrates, and electrolytes can all beobtained while maintaining hydration, the athletewill minimize the gastrointestinal issues that oftenresult from eating solid foods during exercise.

How do you determine fluid and electrolyte needsfor “big sweaters”?Athletes who lose excessively large quantities offluid and/or sodium during endurance exercise areoften classified as “big sweaters.” Although sportsbeverages are critical for the health and performanceof these athletes, plain water can also be added into the nutrition/hydration plan for during activ-ity. Some individuals require 64 fluid ounces ormore per hour—that is a lot! If an athlete was toconsume solely sports drinks in quantities to matchfluid needs, the total amount of carbohydrates con-

gaining the performance edge

Suggest endurance athletesstart performing sweat trialsmonths in advance of animportance athletic eventor competition. Changingfluid (as well as food)intake while exercisingshould be incorporatedover time. Gradualincreases in fluid areperceived as lesschallenging andoverwhelming.

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sumed could potentially reach a level that exceedsthe recommended range of 1.0–1.1 grams of car-bohydrates per minute. For example, if an athleterequires 54 ounces of fluid (based on sweat tri-als), this quantity of most sports beverages wouldsupply approximately 94–101 grams of carbohy-drates in 1 hour—far exceeding the recommendedrange of 60–66 grams of carbohydrates per hour.In this example, the athlete should consume 36–40fluid ounces of a sports beverage and then drink anadditional 14–18 ounces of water to meet his or hertotal fluid needs, without exceeding carbohydraterecommendations.

Oftentimes, “big sweaters” will complain of mus-cle cramps during training sessions and competitions.Muscle cramping is mainly due to inadequate fluidconsumption and dehydration. By performing a sweattrial and developing a hydration plan based on indi-vidual needs, cramping issues are often resolved. Af-ter an inquiry on the fluid choices of big sweaters, it

is often revealed that they aredrinking mainly water (versusa sports beverage) duringtraining sessions. By switch-ing from water to sportsdrinks, thereby supplyingsodium, potassium, and otherelectrolytes lost in sweat, a sec-ond line of defense againstmuscle cramps is established.If these two approaches do notwork, the athlete should seekprofessional help from a dieti-tian, physician, and athletic

trainer. In some cases, athletes are not only “bigsweaters,” but also “big salt sweaters,” meaning theyare losing excessive amounts of sodium and other elec-trolytes due to higher concentrations in their sweat,which in turn causes muscle cramps. For big saltsweaters, an electrolyte supplement in addition to asports beverage may be indicated. The provision ofspecific electrolyte supplements on a regular basisshould be monitored by a physician to avoid any com-plications and to ensure supplements are taken safely.The excessive consumption of electrolyte supplementscan disrupt the electrolyte balance in the body and ul-timately alter heart function.

How do you determine electrolyte needs for ultra-endurance athletes?Ultra-endurance athletes, even those who are notconsidered big salt sweaters, may require additional

sodium during long-duration training sessions andcompetitive events. Sodium losses are estimated at50 mmol per liter of sweat, or 1 gram per liter, dur-ing exercise, with a range of 20–80 mmol per liter.Therefore, sodium requirements for athletes par-ticipating in training sessions and competitions last-ing longer than 4–6 hours require approximately500–1,000 milligrams of sodium per hour of exer-cise, based on sweat rate.60 If the sodium lost in sweatis not replaced in adequate amounts, blood levels ofsodium begin to drop and hyponatremia can ensue.

As mentioned in Chapter 8, hyponatremia is de-fined as blood sodium levels below 130–135 mmol/L.As the duration of an enduranceevent increases, the risk for hy-ponatremia also increases.However, with proper nutritionand hydration planning, it canbe avoided. Salt tablets are com-monly used to boost sodium in-take above what is supplied ina sports beverage for events last-ing longer than 4 hours. Thequantity of sodium in a salttablet can range from as little as150 milligrams up to 1,000 mil-ligrams per tablet. Salt tabletsare sold online and in localpharmacies. Salt tablets shouldbe used in moderation and usedonly to supplement the sodiumobtained from sports beveragesduring training sessions and competitive events last-ing longer than 4 hours. Con-suming sports drinks alone, inadequate amounts, is sufficientfor endurance activity lastingless than 4 hours.

To reiterate the importanceof monitoring intake, cautionshould be taken to ensure thatexcessive sodium is not ingested.Salt tablets are not required ona daily basis. The average Amer-ican diet provides adequatesodium to replace losses throughsweat. If necessary, additionalsalt can be consumed by usingthe salt shaker at the table insmall amounts. Refer to the example in the followingFortifying Your Nutrition Knowledge section regard-ing Mark, a half-Ironman triathlete, which demonstrates

gaining the performance edge

Remember that eachathlete is different. Someathletes can digest andtolerate morecarbohydrates and fluidthan the recommendedranges. Trial runs andpractice will fine tune anutrition plan in preparationfor hard training days andcompetitions.

gaining the performance edge

Remember to usemoderation with sodiumintake. Replacing sodiumlosses is important for theprevention ofhyponatremia; however,excessive amounts ofsodium intake on a regularbasis can contribute to highblood pressure. Use salttablets discriminately andconsume salty foods andtable salt in moderation.

gaining the performance edge

Some sports beveragecompanies have recentlydeveloped formulascontaining almost twice asmuch sodium as regularsports beverages.Endurance athletes regularlyengaging in training andcompetitive sessions lastinglonger than 4 hours shoulduse the higher-sodiumversions. Look forbeverages containingapproximately 175–200 mgof sodium per 8 fluidounces of the beverage.

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Your Nutrition Knowledge

FortifyingYour Nutrition Knowledge


Mark contacted a dietitian to help him determine how to prevent the cramping he was experiencing dur-ing long bike rides and runs while training for a half-Ironman triathlon (1.2-mile swim, 56-mile bikeride, 13.1-mile run). He was baffled regarding the source of the problem because he had been takingthree salt tablets an hour (150 milligrams per tablet) during long workouts since a training partnerhad suggested that low sodium levels were most likely the culprit of his cramps. Mark also reported thathe was drinking plenty of water—consuming a full 20-oz water bottle an hour during training.

The dietitian asked Mark to perform a sweat trial to determine the amount of fluid loss he was ex-periencing during training. After performing the trial and reporting the results, the dietitian informedMark that he was only meeting a portion of his fluid needs. Mark was losing 32–36 ounces of fluidper hour and only replacing 20 ounces. In addition to not meeting his fluid needs, he was also fallingshort on his sodium intake. Even though he was taking salt tablets, he was consuming only 450 mil-ligrams of sodium per hour because he was drinking solely water, which provides no sodium. The die-titian calculated his total fluid, carbohydrate, and sodium requirements and helped Mark develop anutrition and hydration plan for the race using the following steps:

1. The first step was to determine his fluid needs. As stated above, the sweat trial results revealed afluid loss of 32–36 ounces of fluid per hour.

2. The next step was to determine how much carbohydrate and sodium would be supplied if all ofhis fluid needs were met by a sports beverage. Thirty-two to thirty-six ounces of a sports beverageper hour supplies approximately 56–63 grams of carbohydrates and 440–495 milligrams of sodiumper hour, depending on the brand used. A sports beverage is preferred over water because fluid,carbohydrates, and sodium can all be provided, versus only fluid supplied in water.

3. The quantity of carbohydrates supplied through the sports beverage was sufficient to meet his needsduring exercise, although on the low end of the range. Mark can consume carbohydrate gels, energybars, bananas, or other foods to supplement the carbohydrates supplied through the sports beverage.

4. Mark had been consuming approximately 450 milligrams of sodium through salt tablets. This quan-tity of sodium was just slightly below the minimal level of sodium recommended per hour, whichmay have been contributing to his muscle cramps in addition to dehydration. Preferably, sodiumwould be obtained by drinking a sports beverage that simultaneously supplies fluid, sodium, andcarbohydrates for optimal performance and hydration. In Mark’s case, basing his intake of asports beverage solely on fluid needs, the quantity of sodium supplied by the sports beverage isslightly below the 500-milligram minimum level recommended per hour. If he consumes 440–495milligrams of sodium in the sports beverage, an additional 150–500 milligrams needs to be obtainedfrom other sources. If he chooses to use an energy gel, bar, or peanut butter/cheese crackers forfood during the bike portion of the triathlon, then additional sodium will be supplied in small quan-tities from these foods. By also planning on taking 1–2 salt tablets per hour, 150 milligrams of sodiumper tablet, Mark can easily reach the goal of 500–1,000 milligrams of sodium per hour.See Training Table 12.3 for an excerpt of Mark’s half-Ironman plan focused on his needs during the race.

The plan is designed to prevent muscle cramps by supplying adequate fluids and sodium while alsoproviding the carbohydrates needed to keep him performing at his best.

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Training Table 12.3: Mark’s Half-Ironman Nutrition/Hydration Plan

Total Time = 45 minutesno food or drink

Total Time = 3:18 (∼17 mph)

Hour Elapsed on the Bike Food/Fluid Fluid (oz) Carbohydrates (g) Sodium (mg)

1 32–36 oz sports beverage* 32–36 56–63 440–4951 salt tablet** 150

2 32–36 oz sports beverage 32–36 56–63 440–4951⁄2 energy gel*** 14 251 salt tablet 150

3 32–36 oz sports beverage 32–36 56–63 440–4951 salt tablet 150

18 minutes 10–12 oz sports beverage 10–12 18–21 138–165

Average intake on Bike 32–36 oz/hour 60–67 g/hour 580–638 mg/hour

Total Time = 1:51 (∼8:30 min/mile pace)

Aid Stations on Course atMile Markers Food/Fluid Fluid (oz) Carbohydrates (g) Sodium (mg)

1 5 oz sports beverage 5 9 692 5 oz sports beverage 5 9 69

1 salt tablet 1503 5 oz sports beverage 5 9 694 5 oz sports beverage 5 9 695 5 oz sports beverage 5 9 69

1 salt tablet 1501⁄2 energy gel 14 25

6 5 oz sports beverage 5 9 697 5 oz sports beverage 5 9 69

1 salt tablet 1508 5 oz sports beverage 5 9 699 5 oz sports beverage 5 9 6910 5 oz sports beverage 5 9 69

1 salt tablet 15011 5 oz sports beverage 5 9 6912 5 oz sports beverage 5 9 6913.1—strong to

the finish!

Average intake on Run 32 oz/hour 66 g/hour 785 mg/hour

*Using a sports beverage with 14 grams of carbohydrates and 110 milligrams of sodium per 8-oz serving**Using a salt tablet with 150 milligrams of sodium per tablet***Using an energy gel with 28 grams of carbohydrates and 50 milligrams of sodium per gel

Swim 1.2 miles

Bike 56 miles

Run 13.1 miles

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the development of a race-day nutrition plan includingthe appropriate use of salt tablets.

Are fluids needed for recovery from enduranceexercise?Absolutely! Endurance athletes can potentially losehuge quantities of fluid while exercising, which needto be replaced as quickly as possible after exercise.As highlighted in Chapter 8, endurance athletesshould:� Drink fluids to replace any weight loss during

endurance exercise. For every pound lost, anathlete should consume 16–24 ounces of fluid.

� Consume fluids slowly and gradually, insteadof through a large bolus of fluid in one sitting.Athletes should begin drinking immediately af-ter exercise and then continue to drinkthroughout the day.

� Ideally consume fluids containing carbohy-drates, sodium, and potas-sium, which help tomaximize not only fluid re-plenishment, but alsoglycogen stores and lostelectrolytes. Sports drinks,vegetable and fruit juices,milk, and smoothies are ex-amples of fluids containing

more than just water.Fluid replenishment ranks

as high as carbohydrate re-plenishment on the recoveryimportance list for enduranceathletes. Athletes should strivefor consuming individuallyoptimal amounts of fluids ina timely manner.

What meal planning/event logistics need to be considered during endurance events?

The nature of the sport will be a major factor indetermining a specific nutrition plan for an enduranceathlete. Endurance training prepares athletes forevents that can last minutes, hours, or days. Train-ing may occur in a controlled environment or can beheld in a remote area with limited access to facilities.When developing a nutrition plan for endurance ath-letes, the feasibility of consuming foods or fluids,length of the event, availability of refrigeration/heat-ing equipment, and space for carrying supplies mustbe considered.

How can a nutrition plan be developed for sports thatare not conducive to consuming foods or fluids whileexercising?Long distance swimming, mountain biking, and row-ing events are examples of sports that do not lendthemselves to easily consuming foods and fluids dur-ing an event. Swimming and rowing involve bothupper and lower body movement, requiring an ath-lete to come to a complete stop in order to eat ordrink. In a competitive environment, coming to ahalt will translate into the loss of precious secondsor minutes to competitors. In rowing, carrying anyfood or fluid will add weight to the boat, thus po-tentially slowing the athlete and negatively affectingperformance. Mountain biking requires concentra-tion and attention to the course, with legs needed forpedaling while arms and hands are steering the bikeand keeping it upright and on course. In these situ-ations, proper nutrition before and after the eventwill be critical in supplying nutrients and fluids tothe athlete, because minimal consumption will oc-cur during exercise.

Several factors should be considered in the daysprior to and immediately before training or compe-tition. Consuming higher levels of carbohydratesin the 3–4 days prior to an endurance competitioncan supercompensate muscle and liver glycogenstores. This allows additional energy stores to beavailable during long events where carbohydrate con-sumption is logistically impossible. The nutrients andfluid supplied in the hours leading up to the eventwill be the fuel used during exercise. If an athleteruns short on calories, carbohydrates, or fluids, per-formance will suffer because ad-ditional nutrients will not beconsumed during the activity.Athletes should consider eat-ing a larger preactivity meal,which might also mean plan-ning additional time before atraining session or event to al-low for the digestion of themeal. Athletes should continueto sip on fluids between thepreactivity meal and the be-ginning of a training session orcompetition to ensure properhydration. Athletes also needto plan ahead and pack food and beverages to beconsumed immediately following the activity to re-plenish lost nutrients and fluids.

gaining the performance edge

Euhydration is not a staticstate; therefore, maintainingeuhydration should be adaily focus for enduranceathletes. Optimalperformance hinges on anathlete’s correct estimationof fluid needs before,during, and after trainingand competitions. It iscritical for athletes to knowtheir individual sweat ratesand daily fluidrequirements and followthrough with diligent andappropriate fluidconsumption. gaining the performance edge

If the sport is not conduciveto eating and drinking whilemoving, athletes mustplace a strong emphasis onconsuming nutrients andfluids before and after theevent. Encourage athletesto plan ahead and packcoolers of food and drinksto have nutrition easilyaccessible wheneating/drinking is feasible.

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There are some exceptions to the rule. For ex-ample, several ultra-endurance open water swimmingevents allow support boats to follow swimmers, giv-ing the athletes a chance to stop, drink or eat, and thencontinue swimming. The following is an example ofa swimmer, Amy Krauss, who is a four-time com-petitor in the Key West Open Water Swim—a 12.5-mile event circling the island of Key West in 1 day.

Ultra-marathons and adventure races have explodedin popularity, drawing recreational and elite athletesinto events lasting 8–24 or more hours. When eventsare spanning the majority of one day, energy ex-penditure increases dramatically while simultane-ously making it challenging to consume enough fuelbecause regular meals are essentially skipped.

Fortunately, these ultra-endurance sports are con-ducive to eating and drinking while moving, thoughonly in small quantities at a time. In some cases, aidstations with supplies may be available on the racecourse, whereas other events are self-sustaining.

In cases when an athlete is planning on relyingon aid stations for food and fluids, planning andpracticing before an event is paramount. Athletesshould contact the race director or consult the raceinformation packet or Web site to discover what typeof food and fluids will be available on the course.Athletes should then consume the same type of foodand fluid throughout their training. For example,Barbara, an ultra-marathoner, typically uses All-Sport, oranges, and PowerBars during her training.She registers for a race and discovers that Gatorade,bananas, and fig bars are going to be supplied on thecourse. Barbara should immediately switch to usingthese products and foods during her training. Eventhough All-Sport, oranges, and PowerBars are nu-tritionally similar to Gatorade, bananas, and fig barsthey are not identical and can potentially cause tasteaversions and gastrointestinal problems if an athleteis not accustomed to the products. As the length ofan endurance event increases, nutrition becomes evenmore critical to performance. As with any sport, thereshould be no surprises on race day! Athletes should

Key West 12.5-Mile Open Water Swim. Most openwater swims consist of a 1-, 2-, or 6-mile course. TheKey West Open Water Swim is an incredible12.5-mile swim completed in one session. During theevent, each swimmer must have a kayaker followingalongside for safety reasons (see ). Theaccompanying kayak also provides the opportunityfor the competitors to have access to fluids and foodduring the event. On average, it will take a swimmer4–6 hours to complete the race. By maintainingproper hydration and supplying a steady stream ofenergy to the body, the swimmer can perform at hisor her best.

Over the years Amy has experimented with vari-ous hydration/fueling schedules, including differentfluids, food, and nutrition products, to determinewhich options taste appealing and digest easily whileswimming. Her hydration goal has been to drink24 ounces of fluid per hour, which is achieved bystopping to drink every 15–20 minutes. Amy alter-nates between water, sports drinks, and more con-centrated recovery-type nutrition drinks to supplyfluids, carbohydrates, and electrolytes. In addition tofluids, Amy consumes sports gels and small pieces ofenergy bars to supply more calories and carbohy-drates to her muscles.

Although the kayaker makes it easy to have flu-ids and food available at any time, it is not alwayseasy to eat and drink. Depending on the roughness ofthe water, actual ingestion of fluid and food can bechallenging. The constant bobbing of the body in thewaves can lead to seasickness and vomiting, which isobviously detrimental to athletic performance. Amyexperienced this scenario in the 2000 race when shehad to stop to tread water for 90 minutes while vom-iting. She now takes medication several days beforethe race to prevent the seasickness, allowing her toconsume fluids and food comfortably, which has ledto several great race performances.

Figure 12.6

How can a nutrition plan be developed for sportslasting 24 hours or longer?Ultra-endurance events once reserved for really“crazy” people are now becoming more mainstream.

Swimmer Amy Krauss during the Key West OpenWater Swim. Having support staff carry fluids and foods in longdistance endurance races makes adequate replenishment ofneeded nutrients more likely.

Figure 12.6

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find out what products are going to be suppliedduring their scheduled races and then practice, prac-tice, practice during training.

Another issue to address during 8–24+ hourevents is the variety of flavors and textures of foodconsumed. A common compliant of ultra-enduranceathletes is flavor fatigue for sweet products. Sportsdrinks, bars, and gels are made of carbohydratesthat taste sweet—some more intensely than others.When an athlete is consuming these foods over 1–4hours, flavor fatigue is not typically a concern. How-ever, when athletes are consuming large quantitiesof food in order to meet the energy needs of eventslasting more than 8 hours, flavor fatigue is a real-ity that must be addressed during training. If anathlete gets “tired” of the sweet taste, and all heor she has practiced consuming during training issports drinks, fruits, and bars, then a switch to dif-ferent foods or fluids during a race can be disas-trous. Athletes should practice consuming foodsand fluids with salty or bland flavors to balancewith sweet items. Examples of salty items that arecommonly used in races are pretzels, peanut buttercrackers, chicken broth, sesame sticks, and even

lunchmeat sandwiches. Con-tinuing the ingestion of calo-ries will ensure an athletekeeps moving forward onpace, and feeling good.

In an adventure race,when many different sportsare involved in one eventand athletes are typicallyself-supporting, the timing offood and fluid intake as wellas the reliance on nonper-ishable items makes the nu-trition plan unique. Keep inmind that nutrition plansneed to include an athlete’s

favorite training foods and fluids, while maintainingthe feasibility of transporting the items while mov-ing and ensuring food safety. For example, an ad-venture racer might really enjoy eating a turkeyand cheese sandwich 10 hours into a race. How-ever, if the race is self-sufficient and without accessto refrigeration, keeping a lunchmeat and cheesesandwich outside refrigeration for more than2 hours will increase the risk for a foodborne ill-ness. A peanut butter and jelly sandwich or turkeyjerky might be better options.

How can a nutrition plan be developed for a multi-dayevent that will be fully supported?Multi-day endurance events, or stage events, maybe fully supported with team vehicles and overnightaccommodations supplying refrigeration and cook-ing capabilities. These types of events are logisti-cally much easier to plan for because athletes canin some cases stay on a “normal” schedule of eat-ing meals and snacks. The variables to consider inthis type of scenario are the refrigeration, prepa-ration, and storage space for supplies as well as thelength and frequency of exercise during the multi-day event.

An example of this type of event is the RaceAcross America (RAAM). RAAM, first held in 1982,is a nonstop cycling event across the United States.The 2,900–3,000 mile race begins on the west coastand travels across the mountains and plains to theeast coast. Racers can enter the event as a solo rideror as a 2-, 4-, or 8-person team. Individuals and teamsare allowed to have multiple support vehiclesthroughout the race and along the course. Most com-petitors will have a motor home to allow for mealpreparation and vans to fetch additional supplieswhile the cyclists continue to progress en route. Train-ing Table 12.4 gives an example day of meals, snacks,and fluids consumed by a rider on the 4-man Team70+ in 1996.

How can a meal plan be developed for a sport such as a long distance triathlon that includes anonconducive eating environment, a length of timespanning several meals, and race course support?The sport of triathlon has exploded in popularityin the past decade. Triathlons can be categorized intofour distances: Sprint (500-meter swim, 10-mile bikeride, 5-kilometer run), Olympic (1.5-kilometer swim,40-kilometer bike ride, 10-kilometer run), half-Ironman (1.2-mile swim, 56-mile bike ride, 13.1-milerun), and Ironman (2.4-mile swim, 112-mile bikeride, 26.2-mile run). Sprint and Olympic distanceraces can be completed within 1–3 hours for a ma-jority of competitors, requiring a proper preracemeal, a strong focus on hydration, and minimalamounts of sports bars, gels, and other foods dur-ing the race. However, the half and full Ironman dis-tance races can last 4–17 hours, making nutrition acritical component of race day success. Triathlon isunique due to the three sports included, each pro-viding a different environment and plan for hydra-tion and fuel consumption. No food or drink is

gaining the performance edge

Encourage athletes toresearch what products willbe supplied on the racecourse so the identicalproducts can be usedduring training. Be creativewhen developing anutrition plan for eventslasting 8–24 or morehours—include differentflavors, textures, and types of food and fluids.

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available during the swim portion of a triathlon,making prerace nutrition and hydration a top pri-ority. The bike segment of the race is most conduciveto drinking and eating. Bikes can carry fluids in bot-tles attached to the bike frame, behind the seat, andin specialized bottles that fit within the aerobarsplaced on the front of the bike. Athletes can packtheir own food to be carried in the back pockets ofa bike jersey or in a variety of bike bags, pouches, or“boxes” that attach to the bike frame or seat. Thisallows an athlete to drink and eat gradually through-out the bike segment of the race, playing a little“catch-up” from the swim and “stocking up” beforethe run. Because biking is nonimpact, athletes ex-perience fewer gastrointestinal issues with eating anddrinking while cycling as opposed to running, andtherefore the second segment of a triathlon is an idealtime for fueling. The nutrition plan for the run is typ-ically developed around what is available on thecourse at aid stations. Some athletes choose to relymainly on their own fluid and food choices by wear-ing belts with bottle holders and pouches for food.However, for the Ironman distance races, the amountof fluid and fuel needed during the marathon willexceed the carrying capacity of the belt. Therefore,a combination plan of self-support and race coursesupport may work best. One other opportunity forfood and fluid consumption occurs during the twotransitions during a triathlon—one after the swimand the second after the bike segment. During shortertriathlons, athletes aim to keep transition time to aminimum, often choosing not to take time to con-sume anything during transition. In longer distancetriathlons, during transition is an ideal time for chang-ing clothes, taking a minute to rest before the nextsegment of the race, and consuming small amountsof food or fluids.

The Ironman distance is by far the most tax-ing and most reliant on proper nutrition and hy-dration. Training Table 12.5 provides an example of theIronman plan followed by Heather Fink when shecompleted Ironman Coeur d’Alene in 2003. Herrace and nutrition plan progressed flawlessly, al-lowing her to qualify for the Hawaii Ironman in thefall of 2003.

Training Table 12.4: Jack’s Meal Plan during RAAM

Jack Boyer was a 70-year-old member of Team 70+. Hewas 5’8″ and weighed 158 pounds. His daily energy andcarbohydrate needs, accounting for 4–8 hours of cyclingper day, were estimated at 5,422 calories and 990 gramsof carbohydrates. In order to meet this goal, he was in-structed to consume the following each day:• 6 liters of Cytomax sports beverage, supplying

1,278 calories and 360 grams of carbohydrates• 1 “Meal A,” supplying 1,100 calories and 150 grams

of carbohydrates• 2 “Meal Bs,” each supplying 800 calories and

120 grams of carbohydrates• 12 snacks, each supplying 120 calories and 20 grams

of carbohydratesMeal options included, but were not limited to: oatmeal,dry cereal, spinach lasagna, turkey chili, stuffed potatoes,bagel sandwiches, and pasta dishes. Snacks were eatenduring breaks from cycling. Snacks included, but were notlimited to: PowerBars, granola bars, GatorPro, Gatorlode,pretzels, bagels with jelly, dry cereal, trail mix, peanut buttercrackers, and Ritz snack crackers. The four-man team wassplit into two subteams. The subteams alternated 8-hourshifts—8 hours in the motor home resting, eating, and get-ting massages, alternating with 8 hours of cycling. The8 hours of cycling by each subteam of two men was thensplit into alternating 1-hour time blocks of riding and thenresting in the van following directly behind the cyclist onthe road. All meals were eaten in the motor home whilesports beverages and snacks were consumed during the8-hour shift of cycling.

Because the motor home had a refrigerator and a mi-crowave, foods could be prepared for the team on-site.However, most of the food was prepared before leaving onthe adventure and frozen, minimizing the time and effort ofmeal preparation during the race. Therefore, the menu wasplanned around foods that could be reheated well, madefrom scratch in a microwave, or prepared with no cooking.A small cooler was taken during the 8-hour shift of cyclingallowing for drinks and other foods to stay cold.

Jack, as well as the other three riders, was monitoreddaily through a food record and by obtaining body weightsbefore and after 8-hour riding shifts. The riders stayed onplan for the entire race, feeling good and riding strong.Tastes changed during the ride, requiring the menu to beflexible, allowing for foods from restaurants and “interest-ing” requested combinations such as baked potatoes withraisins, milk, and salt. The nutrition plan fueled Jack and therest of the 70+ Team to a successful RAAM finish of 9 days,2 hours, and 27 minutes.

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Training Table 12.5: Heather’s Ironman Nutrition/Hydration Plan

After 5 years of competing in sprint through half-Ironman distance triathlons, in 2003 Heather decided to participate in an Iron-man distance race. Ironman Coeur d’Alene, held in late June and located in northern Idaho, involved a cold swim in Lake Coeurd’Alene; a challenging bike course with several tough, steep hills; and a relatively flat run course. Heather, being a dietitian, knewthe importance of practicing her race day nutrition throughout her training, and therefore developed a proposed plan by Januaryand spent the next 4–5 months refining the plan for race day. From past experience in triathlons, she knew sports beverages, gels,and bars worked well and settled well for her during races. However, she knew she would need to intake more energy andsodium during Ironman and therefore began experimenting with other foods, drinks, and products. The schedule below was theresult of using tried-and-true products, newly discovered products, and beverages/foods known to be available on the race course:

Breakfast (4 hours prior to race start)• 11⁄2 cups dry cereal with one scoop of protein powder and 1 cup soy milk• 1 banana and 8 ounces of orange juice• Sips of Gatorade between breakfast and race start

• No food or drink

Transition #1 (after swim, before bike; Total time = 3:36)• 1⁄2–1 can of Ensure

Nutrition Goals During the Bike Ride: 32 ounces of fluid per hour (specifically, Gatorade), 70–75 grams of carbohydrates perhour, and 500–750 mg sodium per hour. Plan was broken down into 10-mile increments because aid stations were located every10 miles on the bike course. Three 24-ounce bottles of Gatorade were placed on the bike at the beginning of the race and re-placed throughout the course. A Bento Box was attached to the bike frame holding salt tablets, Baker’s Breakfast Cookies, peanutbutter crackers, and one gel. The specific nutrition plan for the bike ride progressed as follows:• 10 miles—Bottle pick-up• 20 miles—3⁄4 of a Baker’s Breakfast Cookie• 30 miles—Bottle pick-up• 40 miles—3 peanut butter crackers• 50 miles—Bottle pick-up + one sodium tablet (1,000 mg)• 60 miles—1 gel• 70 miles—Bottle pick-up• 80 miles—3⁄4 Baker’s Breakfast Cookie• 90 miles—Bottle pick-up• 100 miles—3 peanut butter crackers + one sodium tablet• 110 miles—Bottle pick-up

Transition #2 (after bike, before run; Total time = 2:51)• 1⁄2–1 can of Ensure

Nutrition Goals During the Run: 28 ounces of fluid per hour, 60–65 grams of carbohydrates per hour, and 500–750 mg sodiumper hour. The plan was broken down into 1-mile increments because aid stations were located every mile on the run course. A gelflask filled with four gels was carried during the run with a small plastic pouch attached to the flask to hold several sodium tablets.• 4–6 ounces of fluid were consumed every mile on the course, mainly Gatorade, with a little water, cola (for a flavor change),

and ice cubes.• Half of a gel was originally planned to be consumed every 3 miles during the race for a total of four gels over the 26.2 miles.

However, only 1–2 gels were actually consumed. The temperatures on race day climbed to 97 degrees, increasing the needfor fluids during the race. Due to an increased ingestion of fluids, which contained calories, fewer gels were consumed in orderto stay on track with the planned quantity of carbohydrates needed per hour.

Total Ironman race time = 10:58Second female in 30–34 age group, qualifying Heather for the Hawaii Ironman in October 2003.

2.4-Mile Swim (Total time = 1:05:00)

112-Mile Bike Ride (Total time = 6:02:00)

26.2-Mile Run (Total time = 3:43:00)

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The Box Score 393

Key Points of Chapter:� Endurance athletes expend a tremendous number

of calories not only during competition, but also in the preparatory training. Energy expenditures of6,000–8,000 kcals/day are not out of the ordinary forultra-endurance athletes. This puts a huge drain on en-ergy reserves that must be replenished after daily train-ing bouts and thus makes diet a key factor in athleticsuccess.

� Of the three energy systems, endurance athletes relymost heavily on the aerobic energy system. Appropri-ately designed training programs challenge the aerobicsystem and increase the athlete’s aerobic power sothat he or she can maintain a faster race pace.

� It is critical for endurance athletes to consume suffi-cient calories on a daily basis to supply the energy fordaily training and competition, ensure the delivery ofnutrients needed for complete recovery from work-outs, and stay healthy and injury-free. Daily energyneeds can be estimated using the following formula:Resting energy expenditure × Activity factor.

� Often it is not physically or logistically possible for anendurance athlete to fully match his or her energy ex-penditure with intake during actual training or competi-tion. As a consequence, the event nutrition planshould be based on meeting the performance require-ments of providing carbohydrates, fluids, and sodium.

� The main difference between diets of endurance ath-letes and those of other sports is in the quantity offood consumed, not necessarily the macronutrientcomposition of the diet.

� Carbohydrate intakes of 5 to 10 grams per kilogram ofbody weight are recommended for endurance ath-letes. When expressed as a percentage of their totaldaily caloric intake, carbohydrates should be approxi-mately 50% to 65% for daily training and approxi-mately 65% to 70% during carbohydrate loading.

� Research has demonstrated that consuming carbohy-drates in the hours leading up to an endurance trainingsession or competition is critical for optimal perfor-mance, especially during activities lasting longer than 2 hours. Endurance athletes should be encouraged toconsume a carbohydrate-rich preactivity meal 2–3hours prior to a training session or event and then con-tinue consuming carbohydrates throughout exercise inorder to optimize performance.

� Carbohydrate needs during exercise are estimated at1.0–1.1 grams of carbohydrates per minute of activity,or 60–66 grams carbohydrates per hour for en-

durance athletes. Some athletes can easily consumeand digest upwards of 75–85 grams of carbohydratesper hour, whereas others can barely stomach 45–55grams. Athletes need to experiment with varying quan-tities of carbohydrates surrounding the 60–66 gramrange to determine the best estimate for themindividually.

� Carbohydrate intake is also important after competitionto help replenish glycogen stores. Consuming 1 gramof carbohydrates per kilogram of body weight within15 to 30 minutes after the cessation of exercise pro-vides glucose to muscles at a time when they are mostreceptive to absorbing and storing glucose as glycogen.

� Although protein is not typically used by the body toprovide energy, the extreme energy demands of en-durance training and competition do result in themetabolizing of some protein for energy. As a result,the protein intake recommendation for endurance ath-letes is higher than the current RDA and falls in therange of 1.1 to 2.0 grams per kilogram of body weight.

� The effect of protein intake during competition and itsimpact on performance requires more research; how-ever, for ultra-endurance athletes, the consumption ofprotein seems prudent.

� Despite the fact that fats are a major energy sourceduring endurance sports, high-fat diets have not beenshown to improve endurance performance. The diet ofendurance athletes should include enough fat to ac-count for approximately 20% to 35% of total dailycalories consumed. Immediately prior to training, dur-ing exercise, and immediately after training, fat intakeshould be kept to a minimum while focusing primarilyon carbohydrates and secondarily on protein.

� Vitamin and mineral needs of endurance athletes aresimilar to those of other athletes. However, there are afew vitamins and minerals that should be given partic-ular attention. These include the B vitamins, iron, cal-cium, vitamin C, vitamin E, sodium, and potassium.

� Adequate fluid intake is important for maintaining thehydration status of endurance athletes during their pro-longed training bouts and during competition. Failureto do so can have deadly consequences.

� An excellent way to monitor hydration status is toweigh athletes before and after training or competition.For every pound of body weight lost the athlete shoulddrink 2–3 cups of fluid.

� The risk for hyponatremia increases as the duration ofan endurance event lengthens. As a result, the sodium

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intake of ultra-endurance athletes should be consid-ered when developing a nutrition plan. Sports bever-ages can provide both fluid and sodium; however,pre-event experimentation is critical for successful use.

� Each endurance athlete requires an individualized nu-trition plan. Sport-specific logistics must be consideredin order to plan food and fluid intake appropriately andto implement the plan successfully.

Study Questions1. Can endurance athletes adopt an “eat-as-you-like atti-

tude”? Defend your answer.2. Of the three energy systems, which one do endurance

athletes rely upon most for energy? Under what cir-cumstances would the other two energy systems playa bigger role during endurance competition?

3. What pieces of information would you need as a dieti-tian in order to estimate an endurance athlete’s dailycaloric needs?

4. What is the reasoning behind the statement, “An ath-lete who cuts back on carbohydrate intake is commit-ting performance suicide”?

5. What should the percent composition of carbohydrates,proteins, and fats be for an endurance athlete’s diet?

6. How does the combination of tapering and carbohy-drate loading affect endurance performance?

7. What role do proteins play in regard to the needs of theendurance athlete? What is the current recommenda-tion for protein intake in endurance athletes?

8. For ultra-endurance athletes, is there a training or per-formance benefit to eating a high-fat diet? Should yourecommend eating higher-fat foods during and aftertraining or competition? Discuss why or why not.

9. What are BCAAs and MCTs? What role, if any, do theyplay in meeting the needs of the endurance athlete?

10. What is hyponatremia? Which athletes are at greatestrisk for developing it (be very specific)? What nutritionalstrategies would you use to prevent it?

11. Which vitamins and minerals are of special concern toendurance athletes?

12. What strategies could be employed to help ensure thehydration status of endurance athletes?

13. What is a “sweat trial,” and why is it important to the en-durance athlete?

14. What are some of the logistical and nutritional issuesthat must be dealt with when working with ultra-endurance athletes who are competing in 8+ hourevents?

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