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PEMAKANAN & KECERGASAN

Denise Koh

What is Nutrition?

• The science of food, the nutrients and the

substances therein, their action, interaction,

and balance in relation to health and disease,

and the process by which the organism

ingests, absorbs, transport, utilizes, and

excretes food substance.

Nutrition & Fitness

• A field of study that is concern with the study

of foods and their effect on the human body.

• The central focus of nutrition is the study of

food requirements for the production of

energy and the regulation of bodily processes.

Nutrition & Disease

• 6 out of 10 leading causes of death are chronic

diseases.

• Prevention is the best approach to lessening

one’s chances of getting these diseases

• Physical activity and diet are 2 of the leading

lifestyle factors in the prevention.

YOU ARE WHAT YOU EAT

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Status of Nutritional Health

• Desirable

• Undernutrition

– Depleted nutrient storage

– Reduced biochemical function

– Clinical signs and symptoms

• Overnutrition

– Excess intake of calories and fat

– Obesity

– Use of vitamins and mineral supplements

What is Nutrient?

• A nutrient is a basic substance that is used by the body to sustain vital processes such as repair and regulation of cellular functions and the production of energy.

• 6 classes of nutrients:– Carbohydrates (glucose)

– Fats (2 fatty acids)

– Proteins (9 Amino Acids)

– Vitamins (13 vitamins)

– Minerals (21 minerals)

– water

General Function of Nutrients in Food

• Provide water

• Provide fuel for entire body

• Provide building blocks

• Provide metabolic regulators

General Function of Nutrients in Food

• Carbo, proteins & Fat – give energy and maintenance of body tissue.

• Vitamins and minerals has no calorie count.

– Vitamins have critical role in releasing energy from food.

– Mineral essential to regulation and performance of body function such as maintenance of water balance.

• Water most essential of all nutrients!

Water

• Water is most basic of all nutrients- necessary

to sustain life.

• 60% of body weight

• Essential for both functions as energy

production, digestion, temperature regulation,

and elimination of the by-product of

metabolisme.

Water and Exercise

• Maintaining water balance is very important.

Severe dehydration can cause death.

• Particularly important among people who

exercise, and especially important to those

who exercise in hot and humid weather.

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A Calorie

• A measurement of energy measured in a

bomb calorimeter.

• “the amount of heat it takes to raise the

temperature of 1 gram of water by 1 degree

celsius”

• Food is measure in kilocalories (kcal)

• Calories with a large “C” on nutrition label are

in kcal.

The Energy Nutrient

• Carbohydrates (1g carbohydrates = 4 calories)

– 65-75% of caloies

– Complex vs simple

• Protein (1h protein = 4 calories)

– 20% of kcal

– Unsaturated vs saturated

• Fat (1 g fat = 9 calories)

– 10-15% of kcal

Diet and Health

• A well-balanced diet is important to obtain all

required nutrients for the body.

Ergogenic Aid - Defined

• Substance or device that enhances energy

production, use, or recovery and provides an

athlete with a competitive advantage.

Ergogenic Aid - Examples

• MechanicalMechanicalMechanicalMechanical (shoes)

• PsychologicalPsychologicalPsychologicalPsychological (hypnosis)

• PhysiologicPhysiologicPhysiologicPhysiologic (blood doping)

• NutritionalNutritionalNutritionalNutritional (creatine)

• PharmacologicPharmacologicPharmacologicPharmacologic (anabolic steroids)

Why do athletes use supplements?

• Provide more convenient form of nutrient

• Prevent a perceived deficiency

• Provide direct ergogenic effect

• Belief that every top athlete is taking it; they

can’t afford to lag behind

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Many athletes will do whatever it takes to win…

• In 1995, 198 Olympic-level

power athletes were given

this scenario:

– You are offered a banned

substance with 2

guarantees:

• You will not be caught

• By taking the substance you

will win

Only 3 declined!Only 3 declined!Only 3 declined!Only 3 declined!

• The same 198 athletes were

offered a banned substance

with 2 additional guarantees:

– You will win every event for the

next 5 years

– You will die at the end of those

5 years

50% still said they would use it!50% still said they would use it!50% still said they would use it!50% still said they would use it!

…at any cost

1996-1999 10,449 boys and girls age

12-18 surveyed:

– 4.7% of boys and 1.6% of girls used

protein powder or shake, creatine, amino

acids/HMB, DHEA, growth hormone, or

anabolic steroids at least weekly to

improve appearance or strength

PrevalencePlacebo effect in athletes

• Athletes are HIGHLY

suggestible

– 97% believe placebo

effect works

– 73% said they had

experienced it

– Beedie CJ. J Sports Sci

Med 2007

• “Expectancy Effect” is

significant

– Belief in efficacy �

performance

improvement

• Pill Colors

red/orange/yellow �

stimulant

• Injection > pill

• Expensive > cheap

StimulantsCaffiene

• Is a stimulant found in a variety of foods.

• The IOC classifies it as a restricted drug,

allowing its use up to a certain level.

• Standard is up to a urine level of 12

micrograms/mililiters = 6-8 cups of coffee.

• Absorbed rapidly and shows up in blood

within 15 minites.

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Caffeine’s Proven Effects

– Increased time to fatigue (”capacity”) in wide

range of lab protocols

• Prolonged submaximal (> 90 min)

• Sustained high-intensity (20-60 min)

• Short-duration supra-max (1-5 min)

– Likely beneficial in endurance and “stop-n-go”

sports

– No clear benefit in strength/power events

Caffeine in Endurance Running

• 4.2-sec faster 1.5-km

• 1-3% faster 5-km

• 24-sec faster 8-km

• 50-sec faster 10-km military pack march

• No change in 21-km race

• Improved treadmill time-to-exhaustion in

marathoners

Caffeine in Other Sports

• Rowing: 1-3% faster 2000m

race

• Swimming: 24-sec faster

1500m race

– About 21 min

• Cycling: 3.5% higher mean

power in 40km race

Caffeine Dosing

• Doses 2-9 mg/kg in studies• 2-5 mg/kg usually effective

• 250-500 mg

– Cola: 40 mg

– Coffee: 100 mg

– Tea: 20-100 mg

– Red Bull: 115 mg

– Vivarin: 200 mg

• No difference in fx between “users” and “non-users”

Caffeinated Sports Drinks

• No proven performance benefit

– 18-km run times

– Pl vs carb drink vs carb+150mg

caffeine

– consumed 4x in race

– Int J Sports Med 2005

Effects of Caffeine

• Ergogenic effects varies.

• Effects more pronounced among athletes

whom do not regularly consume caffeine.

• Athletes who abstained from caffeine for a

period of days prior to its use also have more

pronounced effects.

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Side effects of caffeine

• Very rapid heart rate

• Diuresis

• Insomnia

• Nervousness

• Diarrhea

• anxiety

Carbohydrate Loading

• Glycogen stored in the liver and active muscle

supplies most of the energy for intense

aerobic exercise.

• As the exercise period gets longer, glycogen

stores become diminish and fat metabolisme

becomes larger contributor to energy

production.

• This leads to fatigue

Carbohydrate Loading

• Physiologists have known for a long time that

a high carbohydrate diet is beneficial to

endurance performance.

Carbo Loading

• Research has shown that a particular

combination of exercise and diet can “pack”

the muscle with glycogen above normal level.

• The procedure is known as carbohydrate

loading

Approach to carbo loading 1

• Classical approach:

– Athletes begin the process of carbo loading 7 days

prior to competition. Athletes deplete glycogen

stores by training till exhaustion. Hard trainig

x4days, rest x3days.

– Also modify diet: first day = 50% carbo; next 3

days = high fat & protein. Next 3 days, 90% carbo.

– On day of comp: have high carbo meal.

Approach to carbo Loading 2

• 5 days before competition

– Decrease workout time by 90 minutes to 40

minutes, while eating 50% carbo.

– After 2 days, reduce workout time from 4o

minutes to 20 minutes, while eating 70% carbo.

– Day of competition, rest and eat 70% carbo.

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Carbo Loading

• Eat 1-5g of carbo /kg weight prior to event

• Eat 1-4g of carbo /kg weight prior to exercise.

• The meal should be easily digestable

• If taken 1 hour before event, then it should be

in liquid form.

Hydration, Energy and Sport Drink

• Exercise – sweat – depleting water in body

• Recommends:

– 4-6 ounces of water for every 15-20 minutes of

exercise

• Fluid replacement:

– Reduce heart rate

– Body temperature

– Athletes perception of fatigue

Creatine

• Most popular nutritional

supplement

• In 2000, >$300 million in sales

in the US

• Replenishes ATP in

anaerobic exercise

– Made in liver, kidneys,

and pancreas

– Dietary sources: meat,

fish

– Stored in skeletal muscle

– Excreted as creatinine in

urine

Creatine

Creatine – disproven effects

• Meta-analysis 2002:

– NO overall benefit on anaerobic performance (weight lifting, sprint cycling, spring running, sprint swimming, kayaking, arm cranking, or jumping/kicking)

– 29 quality studies

• 35% were statistically significant between Cr and Placebo

• 65% NON statistically significant

Creatine – disproven effects

• Meta-analysis 2003:

– No significant difference in field-based athletic

performance (e.g. running, swimming)

Branch JD. Int J Sports Nutr Exerc Metab June 2003

X X XX X XX X

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Creatine – proven

effects

• 2003 meta-analysis of strength efx:

– 8% increase in 1RM strength vs placebo (20% vs 12%)

– 14% increase in # of reps

– Highly variable response

• Body Composition

– Increase in weight and lean body mass by 1-2 kg over

short term

Rawson, Volek. J Strength Cond Res 2003.

• Increases PCr energy availability

– ->Increased effort in resistance training

Creatine Mechanisms of Action

• Increased satellite cell and myonuclei • Increased gene expression for contractile

proteins

– Due to more available energy

• Increased contractile protein synthesis

Creatine Mechanisms of ActionCreatine Mechanisms of Action Creatine - Side Effects

• Studies of 2-10 weeks: no side efx

• Long term:

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Creatine - regulation

• Not banned anywhere

• Surveys suggest ~ 50% of male college

athletes and 1/3 of all NFL players are on

creatine

Anabolic Steroids

• Analogs of testosterone

• More than 100 types

• Forms:– Oral

– Injection

– Topical (gels, creams)

• Prevalence 2009– Jr high: 2%

– 12th grade: 5% (males 7%, >females 2%)

Anabolic Steroids – Proven Effects

• Increase in fat-free mass

• Increase in body weight

• Increase in arm girth

• Increase in leg girth

• Increase in bench press and

squat scores

• Increase in libido

Anabolic Steroids—Disproven Effects

• No effect on endurance exercise

– Males on treadmill

• Eur J Appl Physiol 2006

– VO2max in rats

• Med Sci Sports Exer 2004

Anabolic Steroids - Side Effects

• Hepatocellular

damage

• Cardiovascular

disease (stroke, MI)

• Psychological

disturbance

Effects can sometimes

be permanent!

“Side effects of anabolic androgenic

steroids abuse”Followed body builders for 2 years

• Decr sperm count and fertility index

• Decr HDL (57 � 42)

• No change liver/prostate US, hematological

indices

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More side effects…

MenMen

–– AcneAcne

–– Premature baldnessPremature baldness

–– Prostatic hypertrophyProstatic hypertrophy

–– ProstatitisProstatitis

–– *Injection complications*Injection complications

–– Testicular atrophyTesticular atrophy

–– *Impotence*Impotence

–– **GynecomastiaGynecomastia

• Adolescents

– Premature closure of physes –

stunted growth

– Decreased libido

– Depression

More side effects…

WomenWomen

–– Clitoral enlargementClitoral enlargement

–– Menstrual dysfunctionMenstrual dysfunction

–– MaleMale--pattern baldnesspattern baldness

–– **MasculinizationMasculinization

–– Deepening of voiceDeepening of voice

–– **HirsutismHirsutism

More side effects…Side effects that can be PERMANENT

• Premature growth plate closure

• Testicular atrophy

• Gynecomastia

• Male pattern baldness

• Female masculinization

• Excessive hair growth

• Deepening voice

• Clitoral enlargement

Anabolic Steroid regulation

• Illegal except by

prescription

• Banned by most

international sports body