Download Physiologists

The amount,
composition and
timing of food
intake can
profoundly affect
sports
performance"
"
PHYSIOLOGISTS
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Nutrition

Fitness Testing
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Research

Supplements

Injury Prevention
SCIENCE AND SPORT

Physiology
Body

Psychology
Mind

Biomechanics
Internal
and External Forces
SPORTS NUTRITION
MY PYRAMID REPLACES FOOD GUIDE
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My Pyramid replaces Food Guide
Pyramid to provide food intake
guidance based on age, sex, and
level of daily exercise.
Recommend consuming between
45% and 65% of total calories
from CHO.
Recommend consuming between
20% to 35% of total calories from
Fat.
Recommend consuming between
10% to 35% of total calories from
Protein.
Recommended meal composition
includes 60% CHO, 25% protein,
15% Fat (Institute of Medicine).
OVERVIEW
Nutrient Consumption: Fit & Non-fit
 Dietary Reference Intakes
 Calorie and Macronutrient Needs

 Pre
workout (competition) Meal
 Water
 Carbohydrate
 Fat
 Protein

Adding Mass: Gaining Weight
NUTRIENT CONSUMPTION: FIT
Active people do not require additional
nutrients beyond those obtained in a
nutritionally well balanced diet.
 What physically fit actually eat.

 Small
differences in energy intake (low v high)
 Higher dietary fiber & lower cholesterol intakes
 Diets more closely approach recommendations

Sound human nutrition represents sound
nutrition for athletes.
FOOD FOR ENERGY
Energy from the diet is stored as body fat or glycogen (carbohydrate in
muscles and liver) and can be broken down to provide energy.
Glycogen is the main source of energy during short bursts of activity and
at the start of exercise.
There is only a small store of glycogen in the body, and as exercise
continues the store becomes depleted and the body starts to use some fat
to provide energy. Most people have quite a large store of body fat.
People who are fitter use up their store of glycogen more slowly, and tend
to use their stores of body fat for fuel more readily.
PERIODIZATION OF CALORIE NEEDS*
Carbohydrates to fuel your training!

Preferred fuel for aerobic and anaerobic
energy systems

Delay fatigue in exercise lasting longer than
60 minutes

Essential role in recovery

Strength and power athletes require
approximately 5-7gms/Kg body weight for
hard training

Endurance athletes 7-10gms/Kg body weight
CARBOHYDRATE
Athletic performance limited by
CHO availability
 High intensity + long duration
sports
 High CHO diets maximize
glycogen stores + 
performance
 Requirements sugar/starch,
liquid/solid dependent on:
 Timing + type of physical
activity

CARBOHYDRATE NEEDS*
More intense or prolonged training requires more
carbohydrate
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3 grams/lb body weight for 1 hour training
4.5 grams/lb body weight for 2 hours training.
5 grams/lb body weight for 3 hours training.
6 grams/lb body weight for 4+ hours training.
How many calories per gram of CHO?
Sources: Bread, Tortillas, Bagels, English Muffins, Cereals, Rice,
Pasta, Vegetables, Potatoes, *Fruit, Fruit Juices, Sports Drinks,
Soda Pop, Crackers, Pita, Pretzels, Popcorn
CARBOHYDRATE NEEDS*
Carbohydrate is the optimal fuel for exercise
 Prolonged and intermittent, intense training
depletes carbohydrate (glycogen) stores
resulting in poor performance and fatigue.
 Consume carbohydrate with every meal.
 In general, carbohydrates (CHO) should always
provide at least 55% of total daily calorie (TDC)
intake. Ideally 60-70% of TDC.
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CARBOHYDRATE NEEDS
A.
Before exercise
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B.
C.
pre-exercise fructose absorbs more slowly, but GI distress
consuming rapidly absorbed, high glycemic CHO w/i 1 hr
before exercising accelerates glycogen depletion by causing
insulin overshoot & rebound hypoglycemia.
consuming low glycemic CHO immediately (< 30 min) allows
for relatively slow absorption.
During exercise: 30-60 grams per hour, 5-10 oz of 5-8%
CHO electrolyte drink every 15-20 min or 2 gels per hour;
drink contributes to temperature regulation
After exercise
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To speed up glycogen replenishment, consume 50-75 g
moderate to high glycemic index w/i 15 minutes.
Under optimal CHO intake, takes 20 hrs to replenish glycogen
stores at rate of 5% per hour.
CARBOHYDRATE LOADING:
ONE EXAMPLE OF HOW
Days prior to event
6
5
4
3
2
1
Exercise duration
90 minutes
40 minutes
40 minutes
20 minutes
20 minutes
rest
Carbohydrate intake
5 gm/kg/day
5 gm/kg/day
5 gm/kg/day
10 gm/kg/day
10 gm/kg/day
10 gm/kg/day
CARBOHYDRATE LOADING

Classic Carbohydrate Loading
 Stage
1: depletion
 Day
1: perform exhaustive exercise to deplete
 Days 2, 3, 4: Maintain low CHO food intake
 Stage
2: loading
 Days
 Stage

5, 6, 7: maintain high CHO food intake
3: competition
Modified Loading
 Days
1-3: exercise @ 75% VO2 max, 1.5 hrs, 50% CHO
 Days 4-6: taper exercise duration, 70% CHO
CARBOHYDRATE LOADING
Glycogen Loading: procedure increases muscle
glycogen levels more than normal (1.7 g/100 g).

Normal amount of glycogen packed in muscle: 5 g
glycogen/ 100 g muscle

What is major benefit of carbohydrate loading?
Endurance capacity
 Unless athlete begins competing completely
depleted, exercise < 60 min requires normal
carbohydrate intake
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What is major drawback of glycogen loading?
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Each gram glycogen stores 2.7 grams H2O, makes
“heavy” fuel.
CARBOHYDRATE NEEDS IN INTENSE EXERCISE*
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Successive days of
intense training
gradually deplete
glycogen reserves even
with typical CHO
intakes: staleness.
High CHO diet (80% of
caloric intake) for 3
days increased muscle
_______ and
endurance time.
FLUID INTAKE (CHAPTER 2)*
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Fluid needs = body weight X .67 = ounces you require
daily NOT including exercise
What should you drink:
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Night before: 16 oz. of water before bed
Morning of practice: 16 oz. of water ASA get up
If practice later in day: 16 oz. of water 2 hrs. b4 practice
Pre-exercise: 6-8 oz. water or sports drink 15 min before
practice, try avoid carbonated beverages or caffeine, NO fruit
juices before exercise – can cause loose bowels & gas
During exercise: 4-8 oz. every 15 minutes water & sports drink
alternate between two
Post exercise: 24 oz. for every pound lost w/i 2 hrs. exercise
FLUID, GLUCOSE, AND ELECTROLYTE INTAKE
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Recommendations
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Fluid volume within stomach exerts greatest effect on rate
of gastric emptying.
To maintain a relatively large fluid volume in stomach &
speed gastric emptying, consume 400-600 ml (13.5-20.3
oz) [immediately] 2 hrs before and __?_ 15 min before
exercise;
With subsequent regular ingestion of [250 ml 8.45 oz] ?
every throughout exercise.
To optimize water & CHO absorption use a 6%
carbohydrate-electrolyte solution (not too dilute or too
concentrated).
Adding sodium to rehydration beverage maintains plasma
osmolarity, reduces urine output, motivates.
SODIUM POTENTIAL BENEFIT*
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Sodium benefits ultraendurance athlete
at risk for hyponatremia.
Adding sodium to rehydration beverage
maintains plasma osmolarity, reduces
urine output, motivates drinking.
Theoretically, water absorption across
intestinal mucosa may be enhance by concurrent absorption of
glucose and Na+.
Glucose stimulates sodium absorption, sodium is necessary for
glucose absorption, and co-transport stimulates water’s passive
uptake by osmotic action.
Best ways to replace K & Na post-exercise:

Orange juice & salted pretzels, Baked potato with ketchup or salt
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Nectarine and some Chex mix, Mix of dried apricots and salted nuts
VITAMINS AND MINERALS
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Essential nutrients

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No evidence in U.S. studies that taking vitamin and
mineral supplements improves athletic performance
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Being deficient in vitamins or minerals is rare in the U.S.
compared to the rest of the world
A few studies outside U.S. showed an effect
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Human body needs these to produce energy
Did population studied have some baseline deficiency treated
with these supplements?
Vegetarian athletes are at risk for being deficient in
vitamins B12, D, riboflavin, iron, zinc and calcium

Athletes who are strict vegetarians should take a multivitamin
to prevent deficiencies and a calcium supplement (1000
mg/day) to help prevent bone loss
PROTEIN NEEDS*
Body can’t use more than 1 gram of protein
per pound of body weight!
 Not immediately available as an energy
source for exercise.
 Important for recovery and to boost immune
system.
 Sources: chicken, turkey, soy burgers, fish, eggs,

dried beans, beef, cheese, nuts and nut butters,
pork, milk, veal, shellfish

In general, 15-20% TDC intake.
FAT NEEDS*
Too much can cause cramps
 Not enough can cause fatigue more quickly
 Try to limit high fat foods before and during
exercise.
 Foods to avoid before & during exercise: chips,
ice cream, nuts, nut butters, french fries,
doughnuts, fried meats, pizza, chocolate,
bologna, salami, pepperoni, burgers
 In general, limit TDC intake < 30% fat.
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EXERCISE AND FOOD INTAKE
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Mean energy intakes
peak between ages 16
and 29 years &
declines thereafter.
For individuals who
exercise regularly food
intake balances daily
energy expenditure.
Lack of precision in
regulating food intake
at low end of energy
expenditure leads to
creeping obesity.
EXERCISE AND FOOD INTAKE
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Most obvious
distinction in nutrient
needs between active
and inactive is more
total calories.
Except for high energy
intake at extremes,
daily intake does not
exceed 4000 kCal for
men and 3000 kCal for
women.
EXERCISE AND FOOD INTAKE
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Phelps told ESPN he eats
roughly 8,000-10,000
cal/d, including lots of
pizza & pasta.
Breakfast of champions
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3 fried egg sandwiches
2 cups coffee
5-egg omelet
1 bowl grits
3 slices French toast
3 chocolate chip pancakes
Beijing 4 x 100 freestyle relay, 8-11-08
EXERCISE AND FOOD INTAKE
To support 6’4”, approximately 190#,
training regimen requires ~1,000 cal/hr
while training or racing.
 Probably eats closer to 6,000 cal/day.

EXERCISE AND FOOD INTAKE
Minimum: current wt (lb) X 23 = total calories for males
 Current
wt (lb) x 20 = total calories for females
Relatively high caloric intakes of physically
active men & women usually increase protein,
vitamin, and mineral intake above normal.
 Percentage of calories from energy nutrients
should remain in normal ranges.
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PRECOMPETITION MEAL
Pre-workout meal goal: maximize muscle & liver
glycogen stores providing glucose for intestinal
absorption during exercise & enhance hydration.
Be consumed within 3-4 hours before exercising
sufficient time to digest & absorb.
 Reasons precompetition meal high in CHO:

 Foods
high in lipid & protein digest slowly
 Low CHO meal can hinder performance
Contain 150 – 300 g CHO in solid or liquid
 Benefits of precomp liquid meal: contribute to fluid
needs, absorb rapidly leaving no residue

BASEBALL GUIDELINES*
Off Season
Baseball In Season
20%
Protein
Fat
60%
20%
Carbo
30%
55%
Preseason
25%
15%
Protein
Fat
55%
Carbo
20%
Protein
Fat
Carbo
BASKETBALL GUIDELINES*
Off & Pre Seasons
In Season
20%
60%
20%
25%
55%
20%
Protein
Fat
Carbo
Protein
Fat
Carbo
FOOTBALL GUIDELINES*
Pre & In Seasons
Off Season
20%
30%
55%
60%
20%
15%
Protein
Fat
Carbo
Protein
Fat
Carbo
GOALS*
Adding Mass
Goals for weight & strength gain = 1 lb/wk
 10-14 additional grams protein/day  1 lb
muscle mass/week
 Goals to add 500-100 additional calories/day
 Increase number of meals, not just size meals
 Don’t rely on weight gainers or high protein
powders. Fill you up before get in all calories
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Thank
you