England Athletics Workshop NUTRITION FOR PERFORMANCE By Mistrelle Baker 23 February 2010.

England Athletics WorkshopEngland Athletics Workshop

NUTRITION FOR NUTRITION FOR PERFORMANCEPERFORMANCE

By By Mistrelle BakerMistrelle Baker

23 February 201023 February 2010

Nutrition for Optimal Nutrition for Optimal Health and PerformanceHealth and Performance

Are you eating the right foods to be the best?!!

GENERAL NUTRITIONGENERAL NUTRITIONKey Points :Key Points :

1. Healthy food2. Nutrition for training 3. Recovery and performance

NUTRITION FOR NUTRITION FOR HEALTHHEALTH

Is Your Diet Healthy and Balanced?Is Your Diet Healthy and Balanced?

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 EATINGBALANCED EATING

1. Bread, cereals, potatoes, rice• 55-65% of daily food.

2. Fruit & vegetables• Eat 5 portions every day (include variety)

3,4. Meat & fish / dairy products 10-15% of daily food -choose low fat versions

5. Fats and sugars• 20-25% of daily food - unsaturated fat rather than saturated fat

1.2.

3. 4.5.

1. BREAD, CEREALS, POTATOES, RICE1. BREAD, CEREALS, POTATOES, RICE

Complex carbohydrates Should form basis for meals Combine different forms for each meal Replace fuel stores Optimise performance

2. FRUIT & VEGETABLES2. FRUIT & VEGETABLES

Performance & recovery Vitamins & minerals Iron, potassium, calcium, chromium, niacin, phosphorous, biotin,

zinc, vits A, C, E, B1, B2, B6, B12.

3. MEAT, FISH & ALTERNATIVES3. MEAT, FISH & ALTERNATIVES

Meat & meat products, poultry, fish & fish products, offal, eggs, beans & lentils, nuts, textured veg.

Performance & recovery

Protein

Bone, skin, muscles, hormones, enzymes, haemoglobin and platelets

Muscle growth, repair and maintenance

4. MILK & DAIRY FOODS4. MILK & DAIRY FOODS

Performance & recoveryFat and proteinEnergy source, bone & teeth strength, muscle & tissue

repair

5. FATTY & SUGARY FOODS5. FATTY & SUGARY FOODS

Use fats sparingly! Sweets may be used to aid recovery!

NUTRITION FOR NUTRITION FOR PERRFORMANCEPERRFORMANCE

How can food and drink affect How can food and drink affect performance?performance?

1. Provide and replace fuel stores

2. Repair and strengthen damaged muscle tissue

3. Replace fluid losses

Daily Calorie IntakeDaily Calorie Intake

ENERGY BALANCEFood Intake and Energy Used

Generally… Male young athletes : 3000kcal Female young athletes : 2500kcal

HOW DO YOU KNOW HOW MUCH ENERGY YOU USE?HOW DO YOU KNOW HOW MUCH ENERGY YOU USE? Every day at rest Exercise training and competition

Fuel for SportFuel 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 SportFuel for Sport

2. Medium Intensity Exercise(eg middle distance running)

Fat

CarbohydrateCarbohydrate is the main provider of energy during medium intensity activities

Fuel for SportFuel for Sport

3. Low intensity Exercise:(eg long distance running/cycling)

Fat

Carbohydrate

As duration continues the contribution of fat increases

OHT 5

The effect of different amounts of The effect of different amounts of carbohydrates on muscle glycogen carbohydrates on muscle glycogen levels after exercise (Costill levels after exercise (Costill et al.et al. 1981)1981)

High CHO diet

Muscle GlycogenLevels

Insufficient CHO in diet

Time 0 24h 48h 72h

Practical Recommendations for Practical Recommendations for Carbohydrate IntakeCarbohydrate Intake

Considerations

Type

Amount

Rate

Timing

Daily RequirementsDaily Requirements

125 - 175g55-65% total intakeComplex (⅔) and simple CHO (⅓)

Limited stores of glycogen (800-2000kcal) Dependent on:

Exercise intensity Exercise duration Diet Body size Fitness status

TypeType

1. Glucose, sucrose, maltodextrins (6-8% solution)

2. Liquid versus solid

3. Low versus high glycaemic index foods

Practical RecommendationPractical Recommendation(Type)(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

AmountAmount

Before

During exercise

After exercise

Practical RecommendationPractical Recommendation(Amount)(Amount)

A. BEFORECarbohydrate loading / glycogen

supercompensationBergstrom et al. (1967) : ‘Classical’

3d : Low-CHO diet (<10%) & glycogen depleting exercise

3d : High-CHO diet (>90%) & low activityDay seven = Competition / race

Adverse effectsAdverse effects

InjuryIrritabilityDecreased ability to trainDizzinessFluid lossG-I disturbanceWeight gain

Practical RecommendationPractical Recommendation(Amount)(Amount)

B. DURINGReplace fluid / sweat losses

TemperatureHumidityWind velocityDuration / type / intensity of event

Up to 2 litres per hourSip every 15 minutes

Practical RecommendationPractical Recommendation(Amount)(Amount)

C. AFTER Dependent upon type of recovery

Active Passive rest Muscle damage / soreness Time-course of recovery

See ‘Rate’ for recommendations

RateRate

Factors determining rate of glycogen synthesisDegree of muscle glycogen depletionDegree of insulin activation of glycogen synthaseCHO content of post-exercise diet

Practical RecommendationsPractical Recommendations(Rate)(Rate)

Frequent feedings over first 4-h0.4g maltodextrin, every 15mins

Highest level of glycogen resynthesis

TimingTiming

A. Immediately post-exercise

B. First 2 hours post-exercise

C. Immediate versus Delayed intake

D. 4 hours post-exercise

Practical RecommendationPractical Recommendation(Timing)(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)

Inappropriate Inappropriate CHO IntakeCHO Intake

Inappropriate Inappropriate CHO IntakeCHO Intake

Excess (simple)

Nutritional deficiencies Obesity High cholesterol Dental problems Gastrointestinal irritation

Deficiency (complex) Tissue wasting (extreme) Homeostatic imbalance Severe fatigue Lack of alertness

Identify the purpose of fluid intake in the diet

Summarise the difference between pre-, during and post-exercise fluid intake

Assess problems associated with excess or deficient fluid intake

FLUID INTAKEFLUID INTAKE

WaterWater

~60% of total body weight Intracellular and extracellular

Functions Transport medium Structural part of body tissues A lubricant Component of chemical reactions

Water and ExerciseWater and Exercise

Optimal fluid balance depends on: Environment Type, intensity, duration of exercise Personal palatability Content of fluid intake Rates of gastric emptying Intestinal absorption

DehydrationDehydration

Decrease in total body water

Rapid fatigue Performance reduction

HypohydrationHypohydration

Aesthetic appearance / weight category sports

Athletes voluntarily dehydrate Negative affects upon performance Short-term adverse health effects

HyponatraemiaHyponatraemia

During exercise

Low plasma sodium concentrations Consumption of excess water Sodium intake is low / losses are high

Fatigue Nausea

ElectrolytesElectrolytes

Function Maintain distribution of water within and outside cells Balance of water and electrolytes is maintained by

endocrine and neurological mechanisms Losses

Sweat Prolonged exercise Hot / humid environment

Practical Practical RecommendationsRecommendations

Isotonic drinks contain the same amount of particles as

blood do not prevent the absorption of fluid contain small but useful amounts of

energy (5-8% 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 drinksHypotonic drinks

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 drinksHypertonic drinks

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 Practical Recommendations

BEFORE 2 h : 500ml fluid Glucose / water solution with salts

DURING 600-1200ml.h.-1

Maintain plasma volume Control electrolyte balance

AFTER Replace water and electrolyte losses Solid and fluid intake Continue until urine is pale yellow

Recipes for home-made Recipes for home-made sports drinkssports drinks

1. 60g of glucose dissolved in 1 L of water or diluted sugar free squash. Add 1/5th of tsp of salt.

2. 60-100g glucose polymer dissolved in 1 L of water or diluted sugar free squash. Add 1/5th of a tsp of salt.

3. Fruit juice diluted in the ratio 50:50 with water. Add 1/5th of a tsp of salt to every litre.

4. 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 ConsiderationsOther 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)

Populations at risk include: females teenagers Vitamin C helps absorption

athletes vegetarians

Iron and AnaemiaIron and Anaemia

Iron is well absorbed from animal sources

- less well absorbed from plant sources

Risk of osteoporosis is increased if: Body weight is low Periods are missed or stopped Calcium intake is low due to milk intolerance or low

food intake There is an absence of weight bearing exercise.

CalciumCalcium

Anorexia nervosaIndividuals will be thinBody weight is

maintained by:- very low food intake

Eating DisordersEating Disorders

Bulimia nervosaIndividuals may not be thinBody weight is maintained

by:- use of laxatives- vomiting

Food is eaten in very large quantities during binges

Anorexia athleticaIndividuals will be leanBody weight is maintained

by:- very low food intake- excessive exercise- use of laxatives- vomiting

SUMMARYSUMMARY

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….For further information / advice….

Mistrelle Baker (mbaker@lincoln.ac.uk)

01522 837094