Transcript England Athletics Workshop

England Athletics Workshop
NUTRITION FOR
PERFORMANCE
By
Mistrelle Baker
23 February 2010
Nutrition for Optimal
Health and Performance

Are you eating the right foods to be the best?!!
GENERAL NUTRITION
Key Points :
1.
2.
3.
Healthy food
Nutrition for training
Recovery and performance
NUTRITION FOR
HEALTH
Is Your Diet Healthy and Balanced?
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Carbohydrate - Is it a large proportion of your intake?
Fat - Is it too high?
Fat - Are you avoiding animal fat?
Fibre - Do you include brown or wholemeal starchy
foods?
- Do you eat five fruit or vegetable portions a
day?
Is your diet varied?
BALANCED EATING
2.
1.
4.
3.
5.
Bread, cereals, potatoes, rice
•
55-65% of daily food.
2.
Fruit & vegetables
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Eat 5 portions every day (include variety)
3,4. Meat & fish / dairy products
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10-15% of daily food -choose low fat versions
5.
Fats and sugars
•
20-25% of daily food - unsaturated fat rather than saturated fat
1.
1. BREAD, CEREALS, POTATOES, RICE
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Complex carbohydrates
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Should form basis for meals
Combine different forms for each meal
Replace fuel stores
Optimise performance
2. FRUIT & VEGETABLES
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Performance & recovery
 Vitamins & minerals
 Iron, potassium, calcium, chromium, niacin, phosphorous,
biotin, zinc, vits A, C, E, B1, B2, B6, B12.
3. MEAT, FISH & ALTERNATIVES
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Meat & meat products, poultry, fish & fish products, offal, eggs,
beans & lentils, nuts, textured veg.
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Performance & recovery
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Protein
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Bone, skin, muscles, hormones, enzymes, haemoglobin and
platelets
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Muscle growth, repair and maintenance
4. MILK & DAIRY FOODS
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Performance & recovery
 Fat and protein
 Energy source, bone & teeth strength, muscle &
tissue repair
5. FATTY & SUGARY FOODS
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Use fats sparingly!
Sweets may be used to aid recovery!
NUTRITION FOR
PERRFORMANCE
How can food and drink affect
performance?
1.
Provide and replace fuel stores
2.
Repair and strengthen damaged muscle tissue
3.
Replace fluid losses
Daily Calorie Intake
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ENERGY BALANCE
Food Intake and Energy Used
Generally…
 Male young athletes : 3000kcal
 Female young athletes : 2500kcal
HOW DO YOU KNOW HOW MUCH ENERGY YOU USE?
 Every day at rest
 Exercise training and competition
Fuel for Sport
1.
High Intensity Exercise: (eg field events, sprints)
Fat
Carbohydrate
Carbohydrate is the only provider of energy for high intensity activities
Fuel for Sport
2.
Medium Intensity Exercise
(eg middle distance running)
Fat
Carbohydrate
Carbohydrate is the main provider of energy during medium
intensity activities
OHT 5
Fuel for Sport
3.
Low intensity Exercise:
(eg long distance running/cycling)
Fat
Carbohydrate
As duration continues the contribution of fat increases
The effect of different amounts of
carbohydrates on muscle glycogen levels
after exercise (Costill et al. 1981)
High CHO diet
Muscle
Glycogen
Levels
Insufficient CHO in diet
Time
0
24h
48h
72h
Practical Recommendations for
Carbohydrate Intake
Considerations
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Type
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Amount
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Rate
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Timing
Daily Requirements
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125 - 175g
55-65% total intake
 Complex (⅔) and simple CHO (⅓)
Limited stores of glycogen (800-2000kcal)
Dependent on:
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Exercise intensity
Exercise duration
Diet
Body size
Fitness status
Type
1.
Glucose, sucrose, maltodextrins
(6-8% solution)
2. Liquid versus solid
3. Low versus high glycaemic index foods
Practical Recommendation
(Type)
Within first 6h, high glycaemic index foods or
simple carbohydrates (glucose, sucrose,
maltodextrin) provide the best glycogen
replacement
 Provide a CHO-replacement fluid containing
70-90g of CHO immediately after exercise if the
athlete is unable to consume solid food
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Amount
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Before
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During exercise
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After exercise
Practical Recommendation
(Amount)
A. BEFORE
 Carbohydrate loading / glycogen
supercompensation
 Bergstrom et al. (1967) : ‘Classical’
3d : Low-CHO diet (<10%) & glycogen depleting
exercise
 3d : High-CHO diet (>90%) & low activity
 Day seven = Competition / race
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Adverse effects
Injury
 Irritability
 Decreased ability to train
 Dizziness
 Fluid loss
 G-I disturbance
 Weight gain
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Practical Recommendation
(Amount)
B. DURING
 Replace fluid / sweat losses
Temperature
 Humidity
 Wind velocity
 Duration / type / intensity of event
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Up to 2 litres per hour
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Sip every 15 minutes
Practical Recommendation
(Amount)
C. AFTER
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Dependent upon type of recovery
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Active
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Passive rest
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Muscle damage / soreness
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Time-course of recovery
See ‘Rate’ for recommendations
Rate
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Factors determining rate of glycogen synthesis
Degree of muscle glycogen depletion
 Degree of insulin activation of glycogen synthase
 CHO content of post-exercise diet
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Practical Recommendations
(Rate)
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Frequent feedings over first 4-h
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0.4g maltodextrin, every 15mins
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Highest level of glycogen resynthesis
Timing
A. Immediately post-exercise
B. First 2 hours post-exercise
C. Immediate versus Delayed intake
D. 4 hours post-exercise
Practical Recommendation
(Timing)
100-150g carbohydrate within the first hour
after exercise, depending on body size.
Combine this carbohydrate with some dietary
protein if possible.
 Over 24h, feed 6-8g/kg (f), 8-10g/kg (m)
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Inappropriate
CHO Intake
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Excess (simple)
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Deficiency (complex)
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Nutritional deficiencies
Obesity
High cholesterol
Dental problems
Gastrointestinal irritation
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Tissue wasting (extreme)
Homeostatic imbalance
Severe fatigue
Lack of alertness
FLUID INTAKE
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Identify the purpose of fluid intake in the diet
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Summarise the difference between pre-,
during and post-exercise fluid intake
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Assess problems associated with excess or
deficient fluid intake
Water
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~60% of total body weight
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Intracellular and extracellular
Functions
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Transport medium
Structural part of body tissues
A lubricant
Component of chemical reactions
Water and Exercise
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Optimal fluid balance depends on:
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Environment
Type, intensity, duration of exercise
Personal palatability
Content of fluid intake
Rates of gastric emptying
Intestinal absorption
Dehydration
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Decrease in total body water
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Rapid fatigue
Performance reduction
Hypohydration
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Aesthetic appearance / weight category sports
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Athletes voluntarily dehydrate
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Negative affects upon performance
Short-term adverse health effects
Hyponatraemia
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During exercise
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Low plasma sodium concentrations
Consumption of excess water
Sodium intake is low / losses are high
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Fatigue
Nausea
Electrolytes
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Function
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Maintain distribution of water within and outside cells
Balance of water and electrolytes is maintained by
endocrine and neurological mechanisms
Losses
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Sweat
Prolonged exercise
Hot / humid environment
Practical Recommendations
Isotonic drinks
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contain the same amount of particles as blood
do not prevent the absorption of fluid
contain small but useful amounts of energy (58% carbohydrate solution)
contain a small amount of sodium (salt) to
assist the absorption of fluid
can be drunk before, during or after exercise
without problem.
Hypotonic drinks
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contain fewer particles than blood
do not prevent the absorption of fluid
contain very small amount of energy – not sufficient in
most cases to be useful
can be drunk before, during or after exercise but will not
contribute sufficient energy to be useful in most cases
Hypertonic drinks
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contain more particles than blood
prevent the absorption of fluid
contain high levels of energy
should not be drunk during exercise generally as can
result in dehydration.
Practical Recommendations
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BEFORE
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DURING
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2 h : 500ml fluid
Glucose / water solution with salts
600-1200ml.h.-1
Maintain plasma volume
Control electrolyte balance
AFTER
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Replace water and electrolyte losses
Solid and fluid intake
Continue until urine is pale yellow
Recipes for home-made
sports drinks
1.
2.
3.
4.
60g of glucose dissolved in 1 L of water or diluted sugar free
squash. Add 1/5th of tsp of salt.
60-100g glucose polymer dissolved in 1 L of water or diluted
sugar free squash. Add 1/5th of a tsp of salt.
Fruit juice diluted in the ratio 50:50 with water. Add 1/5th of a tsp
of salt to every litre.
Fruit squash diluted in the ratio of one part squash to 4 or 5
parts water. Add 1/5th of a tsp of salt to every litre.
Chill drinks before serving. Remember that good dental care is
necessary when using sweetened drinks.
Other Athlete Considerations
Travel Within the UK
•Fitting in time to eat uses travel time
•Pack food, snacks and drinks
•Do not rely on venue at competitions
•Remember to drink
Travel Abroad
•Fussy eaters are hard to feed
•Some foods may need to be taken
•Check the venue and foods available
•Check the water is safe
•Avoid certain foods (shell-fish, ice-cream, curries)
Iron and Anaemia
Populations at risk include:
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females
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teenagers
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athletes
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vegetarians
Vitamin C helps absorption
Iron is well absorbed
from animal sources
- less well absorbed
from plant sources
Calcium
Risk of osteoporosis is increased if:
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Body weight is low
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Periods are missed or stopped
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Calcium intake is low due to milk intolerance or low food
intake
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There is an absence of weight bearing exercise.
Eating Disorders
Anorexia nervosa
Bulimia nervosa
Anorexia athletica
Individuals will be thin
Body weight is
maintained by:
- very low food intake
Individuals may not be thin
Body weight is maintained
by:
- use of laxatives
- vomiting
Individuals will be lean
Body weight is maintained
by:
- very low food intake
- excessive exercise
- use of laxatives
- vomiting
Food is eaten in very large
quantities during
binges
SUMMARY
Always eat a balanced diet
 Drink 2 litres of water each day
 Eat plenty of carbs before, during and
after exercise
 Avoid fried and fatty foods where
possible
 Avoid large gaps between meals – ‘little
and often’

Compiled by:
Mistrelle Baker
For further information / advice….
Mistrelle Baker ([email protected])
01522 837094