Sports Nutrition: Eating for Peak Performance

BIOL 103, Chapter 11

Nutrition and Physical Performance

• “Exercise is medicine”• Physical fitness is made up for 5 components:

1. Cardiorespiratory fitness: ability of body’s circulatory and respiratory systems to fuel during sustained physical activity.

2. Muscular strength: ability of muscle to exert force during an activity

3. Muscular endurance: ability of muscle to continue to perform without fatigue

4. Body composition: relative amount of fat to lean body mass.

5. Flexibility: the range of motion around a joint

Figure 11.1 Develop an Active Lifestyle

• To promote health, exercise 30 min/day• To achieve and maintain fitness, 29-60 min of continuous activity or

intermittent aerobic activity, 3-5 days/week

Energy Systems, Muscles, and Physical Performance

1. ATP-CP energy system: – Anaerobic: _____________________________– Quick source of ATP

• Cellular ATP and _____________________________

– Fuel for ___________________ of maximal effort

Energy Systems, Muscles, and Physical Performance

2. Lactic acid energy system– “Acceleration stage”– Anaerobic– Breakdown of _________ _____

and _________________________– Rise in __________ triggers muscle

fatigue• How? A rise in acidity impair

breakdown of glucose and inhibits _______ binding _______________ ______________________________

Energy Systems, Muscles, and Physical Performance

3. Oxygen energy system– “Endurance stage”– Breakdown of ____________ and

_______ for energy in the cell’s mitochondria

• Requires oxygen (Aerobic)• Produces ATP more ____________

because the required oxygen has to travel from lungs all the way to the cell’s mitochondria.

Problem Set 11, Q1

• Name the three types of energy system mentioned in class. Classify them into aerobic and anaerobic. How does each of the system acquire energy?

Energy Systems, Muscles, and Physical Performance

• Teamwork in energy production– Anaerobic systems– Aerobic systems

• Glycogen depletion– Steady drop of glycogen

for first _____________– Entirely depleted at

around _____________

Energy Systems, Muscles, Physical Performance

• Endurance training – Training increases number of _____________

improves _____________ enhances aerobic capacity

– Decreases reliance on anaerobic systems– Extends availability of ____________________

Muscles and Muscle Fibers(Problem Set 11, Q2)

• We have two types of skeletal muscles:– Slow-twitch fibers – muscles that develop tension

more slowly; have high oxidative capacities• __________________________ (aerobic endurance)• Ex: __________________________

– Fast-twitch fibers – muscles that can develop high tension rapidly.

• ___________________________________• Ex: ________________________________

– Relative proportion determined by ____________

Figure 11.10 Mix of your Muscle Fibers• If you are best at events requiring explosive movements, you may

have greater percentage of fast-twitch muscle fibers.• If endurance events are your specialty, you may have more slow-

twitch fibers.

Optimal Nutrition for Athletic Performance

• Consume _________________________ (first priority for athletes)– 6-10g/kg per day of carbs– 1.2-1.7g/kg per day of protein– 20-35% of total calories from fat

• Maintain appropriate body weight and body composition

• Promote ___________________ from training• Maintain hydration status

Carbohydrate and Exercise• High-carbohydrate diets:

– Increase ______________– Extend _______________

• Carbohydrate loading– __________ of calories as

carbohydrate– __________ exercise

intensity prior to competition

– Not very beneficial if the aerobic activity lasts less than _______ minutes.

Problem Set 11, Q3a

• Explain what is carbohydrate loading and why it is beneficial to your running.

Carbohydrate intake and Exercise• Before exercise

– Eating carbs 2-4 hours _________ morning exercise helps replenish glycogen stores and improve endurance

– Recommend ________ portions and ___________ foods/beverages

• During exercise– ___________ (______% carbohydrate + ___________)

for events that last at least 1 hour.• After exercise

– Replenish glycogen stores: 1-1.5 grams carbohydrate per body kg both 30 minutes and 2 hours after exercise

Dietary Fat and Exercise

• Fat– Major fuel source for ________________ activities

• Key point: Endurance training increases the capacity of your oxygen energy system, enhancing your body’s ability to use fat as fuel.

– High-fat diet __________ needed– Recommendations:

• Moderate fat intake: 20-35% of calories• Limits saturated fat to less than 10% of energy• Avoid trans fat as much as possible

Protein and Exercise

• Muscles and strength are built with exercise (not extra protein) and carbohydrates provide the fuel needed for muscle-building exercise.

• Protein recommendations– Adults: 0.8 grams per kg body weight– Endurance athletes: 1.2-1.7 g/kg– Resistance-trained athletes: 1.6-1.7 g/kg

• Protein sources– Foods: lean meats, fish, low-fat dairy, and egg

whites

Proteins and Exercise

• Protein intake after exercise:– Protein combined with carbohydrate consumption

after exercising helps replenish _________ more efficiently.

• Dangers of high-protein intake– Diuresis (loss of body water): high protein high

urine production dehydration + mineral losses• High protein diets are neither recommended

nor necessary.

Problem Set 11, Q3b

• Should you still consume dietary fat and protein for your activity? Why or why not?

Vitamins, Minerals, and Athletic Performance

• B vitamins– Needed for ____________ metabolism

• Calcium– Needed for normal _________ function and bones

• Iron– Needed for ___________ delivery and

______________ production– Athletes have _________ losses from trauma to

the capillaries in the feet.

Fluid Needs During Exercise

• Exercise and fluid loss increase risk for dehydration– Increased losses from _____________ (0.5-2.0 L/hour)– Increased with heat, humidity

• Hydration– Adequate fluids ________________________exercise

• Should drink fluid at rates that match sweat rates– Should you drink water vs. sports drinks?

• Depends on duration and intensity of activities• Depends on environmental factors• If >60 min, high humidity, or very intense events, recommend

______________________________________

Characteristics of Nutrition Supplements and Ergogenic Aids

• Ergogenic aids: substances that can ________ athletic performance– Provide calories– Provide vitamins and minerals– Contribute to performance and enhance recovery– Are believed to simulate and maintain muscle

growth

Nutrition Supplements and Ergogenic Aids

• Table 11.10 Types of Ergogenic Aids– Nutritional, Physiological, Psychological,

Biomechanical, Pharmacological

• Regulation and concerns about dietary and herbal supplements– __________ FDA safety and effectiveness

regulations– Possibility of product contamination

Nutrition Supplements and Ergogenic Aids

• Weight-gain powders– Add an extra 500-1000 calories/day

• ________% weight gain by high calorie diet is muscle, rest is fat

– No proof that increasing protein intake above recommended levels improves _______________

– Too much protein ___________________ fat

Nutrition Supplements and Ergogenic Aids and popular theories

• Creatine – _______________________________• Antioxidants – protect muscles/cells from

exercise damage• Caffeine – nerve/muscle signal facilitator, might

increase ability to break down fat for energy• Sodium bicarbonate (baking soda) – to neutralize

_______________• Chromium – ________________________• Iron – for anemia• Green tea extract – weight loss?