2. Sports NutritionSports Nutrition
Sports nutrition is the study and practice of nutrition
and diet as it relates to athletic performance.
It is concerned with the type and quantity of fluid
and food taken by an athlete, and deals with
nutrition such as vitamins, minerals, supplements
and organic substances such as carbohydrates,
proteins and fats.
Although an important part of many sports training
regimens, it is most commonly considered in
strength sports (such as weight lifting and
bodybuilding) and endurance sports (for example
cycling, running, swimming).
3. ENERGY SYSTEMS
The human body must continuously be supplied
with energy to perform its many complex
functions.
Two metabolic systems energy for the body –
one dependent on oxygen and the other able to
function without oxygen.
Both of these systems provide energy, however,
the use of one system over the other depends on
the duration, intensity and type of physical
activity.
4. ANAEROBIC ENERGY SYSTM
There are to energy system in the body
phosphagen system and lactic acid system hat
can operator in the absence of the oxygen.
These system are capable of producing ATP
energy at a high rate.
They are utilized when the rate of energy
production demanded of the exercise exceeds
that of the aerobic system alone.
The main limitation of this system is the relatively
small amount of ATP that can be made before
fatigue ensues.
5. Aerobic Energy System
The aerobic system supplies all of the energy for low
to moderate intensity exercise.
It supplies energy for sleeping, resting, sitting, walking
and other firms of low intensity physical activity.
As the activity becomes more intense, to the point that
it can only be sustained for a matter of a few minutes,
the aerobic system can no longer provide energy at a
sufficient rate.
At this stage, ATP production is supplemented by the
lactic acid and phosphagen system. Exercise that
relies heavily on oxygen for the provision of energy is
called an aerobic exercise.
6. Energy
Energy requirement of sportsperson and athletes
vary widely depending upon the intensity of the
activity involved.
For the purpose of defining energy requirements,
sports and athletic events are divided into two
broad categories like power and non-power
events, with additional categories representing
activities of different intensities.
7. The energy requirements under power categories
(throwers, sprinters, jumpers, boxing, wrestling,
weight lifting) range from 3500-6000 kcal/day,
while those under nonpower (other athletics,
hockey, volleyball, swimmers) and other skilled
category (archery, Yatching) range from 3500-
4500 kcal/day.
It is important that the daily energy intake is
contributed by carbohydrates, fats and protein.
Percentage energy from these three sources
should be 50-55%, 30 and 15-20% respectively.
8. Carbohydrate
on comparing the average work time on
consumption of mixed diet, high fat/ protein diet
and high carbohydrate diet, the longest work time
was observed with a high carbohydrate diet.
Since the RDA for carbohydrate is 50-55% of
total calories, and many carbohydrate, and many
carbohydrate rich foods are fiber-rich food-which
means lots of chewing and higher satiety due to
the bulking capacity of dietary fiber.
9. However, for athletes with very high energy
requirements of over 3000-5000 kcal a day,
consuming and byproducts are concentrated
carbohydrate foods i.e.,
refined starchy foods, nuts and oilseeds. Milk and
byproducts are advised. Still, a nutrient rich diet
remains central for adequacy sake, while vital,
energy alone is nit enough to support
performance.
10. CARBOHYDRATES
COMPLEX
(contain other
useful nutrients)
Preferred option for carb
intake due to being an
efficient energy source,
readily used.
Stores depleted quickly so
need to be replaced
frequently
SIMPLE
Carbohydrates
stored as
GLYCOGEN in
the muscles and
liver.
Muscles cannot
perform without it.
Therefore need to
be replenished
11. Protein
According to the RDA, a normal person is required
to consume 0.8 g to 1.0 g protein/kg body weight.
Protein intake equal to 15-20 % of total calorie will
meet the protein requirements of most athletes.
ICMR, 1985, recommends 12-14 % of total energy
requirements and upper limit could be placed at 2
g/kg body weight. Consuming more protein than 2.0
g/kg body weight results in increased protein
oxidation, urea formation, diuresis and can increase
risk for dehydration.
12. Vitamins and minerals
Owing to increased energy requirements and
exercise-induced production of free radicals, higher
amounts of B- vitamins with anti- oxidant properties
are required for athletes.
The B-vitamin requirement is 1mg/1000 kcal for
thiamin and riboflavin and10-20mg/1000 kcal for
niacin. Intake of retinol may be placed at 1000-2000
micrograms per day.
Vitamin E, which is an antioxidant should be taken at
the level of 10-20 IU.
Vitamin C, which is also essential for iron absorption,
its intake should be 100-200mg/day.
13. Specially for the female athletes between 13 and
19 year of age. Female athletes, who train
heavily, have a high incidence of amenorrhea
and thus conserve iron stores.
In any case, iron intake should not be less than
50-75 mg for sports men and 60-100 g for sports
women.
14. Vitamin and Minerals
Vitamin
(a) Intake to keep enzymes saturated with adequate
tissue store.
(b) Different additional supplement of certain antioxidant
vitamins and to guard against any dietary
inadequacy.
Minerals
(a) Electrolytes are important-supplements given during
sports events.
(b) Iron : Additional iron supplements to prevent sports
anemia ; Haem iron supplement would be better.
(c) trace minerals : Zn, Cu, Se important. Selenium is
an antioxidant.
15. Nutrition requirement of sports
persons and athletes
Nutrition
Per day Per kg body weight
Energy per
cent derived
from.
Energy, kcal
Protein, g
Fat, g
Carbohydrate, g
Vitamins and minerals
Calcium, g
Iron, mg
Vitamin, A, mg
Thiamine, mg
Riboflavin, mg
Niacin, mg
Vitamin C, mg
3000-6000
135-225
120-200
400-600
1.5-3.0
50-85
1080-2500
3-6
3-6
30-60
80-150
50-80
2-3-5
2-3
6-8
-
15
30
55
Requirement
16. Water and Electrolytes
Water probably has a greater effect on athletic
performance than any other nutrient. Most people
obtain around two thirds of their water intake from
drinking fluids and between 20-40 % from solid foods.
Athletes, on the other hand, must obtain as 90 % of
their water intake by drinking water.
The two group of athletes most vulnerable to
dehydration are marathon runners and wrestlers.
Dehydration is serious problem for athletes.
17. It is important to understand nutritionally related
factors that cause fatigue & reduced
performance.
These being : - depletion of muscle stores
& dehydration
18. Hydration and Performance
• Dehydration leads
to:
• Increased body
temperature
• Elevated heart rate
• Increase in perceived
exertion
• Dehydration affects:
• Performance –
endurance and intensity
• Coordination and skill
• Concentration and
decision making
• Negative effects when
fluid deficits are as low as
2%
19. Requirements of fluid,
carbohydrate and sodium
Type of event
Water ml
Requirement
Carbohydrate g/ liter
Sodium mEq/l
Event lasting
less than one
hour
Event lasting
between 1 to 3
hrs
Event lasting
more than 3
hours
300-500
300-500
(before the
event)
300-500
(before the
event) 500-
1000 ml
60-100( with 500-
1000 ml water)
60-80 (with 800-
1600 ml water)
60-80 (500-1000 ml)
-
-
20-30
20. THE TRAINING DIET..THE TRAINING DIET..
Athletes now understand that they must eat well
to ensure maximum return from heavy training
schedules.
The competition diet is established providing
athletes with knowledge of special eating
practices, before, during and after the event to
maximise their performance.
21. GENERAL PRINCIPLESGENERAL PRINCIPLES
OF SPORTS NUTRITIONOF SPORTS NUTRITION
Recommended balanced diet for average sports
person is….
55 – 60% Carbohydrates
25 – 30% Fats
10 – 15% Protein
Recommended balanced diet for more strenuous
athlete is…
70% carbohydrates
15 – 20% Fats
10 – 15% Protein
22. STRATEGIES TO REDUCE, DELAY OR OFFSETSTRATEGIES TO REDUCE, DELAY OR OFFSET
THESE FACTORSTHESE FACTORS
General preparation of energy stores
(increase carbohydrate intake to ensure natural
storage capacity)
Carbohydrate loading for endurance events
(gradually reduce training early in the week,
maintain normal diet to maintain carb levels –
reduce training further and consume high level of
carbohydrates
80 – 85% of kg intake)
Pre-competition meal
(ensure that glycogen stores are topped up for
strenuous exercise, adequate hydration)
23. STRATEGIES CONT..STRATEGIES CONT..
Carbohydrate supplementation (marathons)
(generally in fluid form in small amounts and frequent
intervals – this maintains blood glucose levels and
spares muscle glycogen)
Glycogen replenishment
(first 15 min after exercise eat foods high in glycogen
e.g. fresh fruit, lollies…..
Following two hours meal high in complex carbs &
protein
Fluid replenishment
Before, during and after
24. Sources, function, usesSources, function, uses
Sources Function Sports of primary use
CHO Breads, cereals,
rice, pasta, fruit &
vegetables
The bodies main source of
energy to carry out every-
day activities
Team Sports
(football, netball
etc)
Protein Beef, lamb, fish,
chicken, eggs
Builds and repairs all body
cells
Marathon (Long in
duration)
Fats Animal Products –
meat, chicken etc
(saturated)
Plants – Avocado
(unsaturated)
Supply essential fatty acids
that form membrane of
cells. Vital in hormone
production
Walking, mowing
lawns
Secondary energy
source when CHO’s
are used
Water Straight from a
tap/bottle, fruits
(oranges, pears)
Transport other nutrients,
cells, hormones & wastes
around the body
All
25. Sport Nutrient Requirements
Each sports person will have different dietary
requirements depending on…
Training
Age
Sex
Body size
Sport played
Environment for training and competition
26. Sport Nutrient Requirements
• Increased energy requirements for growth
• High carbohydrate, moderate protein & low
fat eating plan recommended
• Overall nutritional adequacy is of paramount
importance but particularly iron and calcium
Increased fluid requirements also present
• Basic sports nutrition
principles do apply to children and adolescents
but promoting good nutrition is particularly
important.
27. GUIDELINES FOR A SPORTSGUIDELINES FOR A SPORTS
PERSON DIETPERSON DIET
1.Increase complex
carbohydrates
2.Decrease dietary fat
3.Ensure adequate protein
intake
4.Increase dietary fibre
5.Decrease/eliminate alcohol
6.Decrease salt intake
7.Increase water intake
28. Dietary Guidelines
An adequate, balanced diet is necessary for an
effective performance but does not guarantee it
because nutrition is but one aspect of performance.
A poor diet, on the other hand guarantees substance
performance.
Ingestion of one or more nutrient in amounts much
greater than body needs will not enhance
performance.
Loss of water in sweat is accompanied by a very small
loss of salt relative to the amount in the blood.
Hence additional salt tablets need not be taken.
29. ● A rapidly digested meal low in fat, moderately low
in protein and high in complex carbohydrate
should be eaten 3 to 5 hours before the
competition.
● Coffee, tea, beer and caffeine containing soft
drinks should be avoided. The increased
carbodioxide levels in the digestive tract after
taking carbonated beverages reduce the body’s
urge to take additional fluids. Soft drinks provide
only empty calories.
● Proper fluid balance maintains blood volume,
which in turn, supplies blood to the skin for body
temperature regulation.