Fuel for Performance

Dr Andrew Middlebrooke

www.exercisescienceconsulting.co.uk

Content

Why do we eat and drink? What happens if we don't? What should we eat? What should we drink? How do we maximise performance?

Aim

To increase your knowledge and understanding of nutrition in a sporting context:

– ‘365’ nutrition– Event/training preparation

Why do we eat and drink?

ENERGY

Why do we use energy for?

Development & growth Body function

– 65-70% of total energy expenditure Supply of nutrients (e.g. oxygen) Physical activity/exercise

– 15-30% of total energy expenditure

How do we convert food to energy?

Food and drink is digested and absorbed Can be used immediately or stored

Carbohydrate GlycogenGlucose

Food Muscle/liver

Blood

ATP

The problem with ATP

Body can only store small amounts Stores are used up quickly (<10 secs) Needs to be constantly produced ↑Rate of ATP production from carbohydrate Need to start with glycogen stores full

The problem of energy depletion

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600

0 2 12 24 26 36 48 50 60 72

Muscle Glycogen

HoursHigh Carbohydrate Diet

Low Carbohydrate Diet

=endurance training

Mus

cle

Gly

coge

n

‘Loss of fluid and reduction in the body’s carbohydrate stores are the two major

causes of fatigue in prolonged exercise’ Consensus statement – Maughan et al. Br J Sports Med 1993; 27:34-5

How much energy do we need?

Depends of the duration/type/intensity of exercise

Non-athletes 1800-2500kcals per day Athletes 2200-6000kcals per day!

What do we need to eat?

Carbohydrates Proteins Fat Vitamins Minerals

Food Pyramid

Recap!

Why do we eat / drink? What do we use energy for? How do we use energy? What are major causes of fatigue? How much energy do we need? Where should we get energy from?

Carbohydrate

2 main types– Complex ‘starchy’

Bread, pasta, rice

– Simple ‘sugary’ Chocolate, sweets

Balanced diet; 50-70%from carbohydrate– 6-10g per kg body weight per day– 420-700g per day for 70kg male

How important are carbohydrates?

• Hawley et al. ‘97: Increasing your carbohydrate stores means:

- complete a distance 2-3% quicker (endurance performance)- you can run ~20% further (endurance capacity)

“9/10 times the reason an athlete doesn't reach their personal best is because they're not getting enough carbohydrates and that's what your muscles need for food." (Barbara Lewin 2008)

Food Carbohydrate level (g)

Energy (kcal)

Large portion of pasta

Large portion of rice

Large portion jacket potato

Large tin of baked beans

2 large thin slices of bread

Lucozade Sport 500ml bottle

1 pint of milk

Medium banana

Apple

Food Carbohydrate level (g)

Energy (kcal)

Large portion of pasta 90 360

Large portion of rice 60 240

Large portion jacket potato 45 180

Large tin of baked beans 45 180

2 large thin slices of bread 30 120

Lucozade Sport 500ml bottle 32 128

1 pint of milk 30 120

Medium banana 20 80

Apple 10 40

Proteins

Essential for growth & repair Requirement higher for athletes

– 15% of total energy intake Rough guide:

– Endurance =1.2-1.4g per kg body weight– Strength = 1.6-1.7g per kg body weight

Can be met through diet!

Fat

Concentrated energy source Provides

– Fat soluable vitamins– Essential fatty acids

Relatively low– 25-30% of total energy intake– <10% from saturated fat

Vitamins & Minerals

Essential for:– converting food sources into energy– Maintaining good health

Obtained from natural food sources– Fruit, vegetables, red meat and dairy

5 portions of fruit/veg!

What about hydration?

Approx. 65% of your body is water Important role in many body functions

– 1.5-2 L per day to keep fully hydrated– Sport places extra demands– Body temperature increases/sweating

Need to replace fluid loss otherwise……?

How does this affect performance?

A fluid loss of just 2% has been proven to impair performance

Not just water! Sweat contains various

salts (electrolytes) which also need to be replaced

Just how important is hydration?

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Exercise Capacity (%)

Body Weight Loss (%)

Recap!

How much carbohydrate? How much protein? How much fat? How much fluid?

How do I maximise my performance?

High carbohydrate (60-70%) diet Nutrition routine before, during and after

– Varies dependent upon Time of training/competition Type of event Personal preferences

Pre-competition/training: Eat a high carbohydrate, low fat, low to moderate protein meal 3-4

hours before exercise

Drink 250-500 mL of water ~2 hours before

Eat a carbohydrate based snack 30-60 minutes before

If you are training early in the morning or in the evening - adjust your diet to make sure you are well hydrated and you have adequate levels of fuel.

For example:– make sure you are adequately hydrated before going to bed – eat a carbohydrate rich snack at least 1-2 hours before bed – drink approximately 250-500 mL of water 30-60 minutes before training.

During training/competition

Sip water or a carbohydrate and electrolyte based sports drink during training / race.

75-150 mL every 20 minutes

Post-competition / training: Eat a carbohydrate/protein snack or recovery drink within

30 minutes of finishing the race/training session.

Continue with regular meals to help recovery asap.

Replace lost fluid within 2 hours by drinking fluid equal to 150% of your body weight loss from the exercise

– loss of 1 kg is replaced by 1.5 L of fluid).

Summary

Why do we eat and drink? Energy – replenish ATP / maintain fluid balance

What happens if we don't? Fatigue / reduction in performance

What should we eat? High carb / moderate protein/ low fat diet

What should we drink? 2L per day + training loss

How do we maximise performance? Maintain carbohydrate stores

Question Time!

Contact Details

Dr Andrew MiddlebrookeTel: 07906 502180Email: andrew@exercisescienceconsulting.co.ukWeb: www.exercisescienceconsulting.co.uk