Nutrition and Endurance Performance

Carbohydrates

The relationship between carbohydrate intake and performance has been a much debated topic over the past 10 years.

It is now widely accepted that endurance athletes need to take a high carbohydrate diet to maximise muscle and liver glycogen stores before a long endurance events.  Originally scientists believed that a depletion phase was needed where athletes did exhaustive exercise and ate a diet low in carbohydrate to get the best effect.  Now we understand that tapering training and taking a high carbohydrate diet is as effective and prevents the athlete getting injured. 

We now understand that carbohydrate has a protein sparing effect and that good carbohydrate intake pre and post exercise can help protect the immune system.   Therefore timing of carbohydrate and protein is important; it means that an athlete can train longer and harder with more rapid recovery.

In recent years science has demonstrated how different types of carbohydrate can be used strategically and different times during training and competition to optimise carbohydrate stores and fuel delivery.  The GI index can to help individuals manage their weight more effectively.  High GI carbohydrate such as glucose polymer drinks can be used immediately before or during a long event, providing fuel quickly to exercising muscle.  Whereas low GI foods can make up the bulk of the training diet, to sustain slow releasing glucose help to maintain steady blood glucose and insulin levels. 

Low GI foods – examples include oats, all bran, pasta all types, new potatoes beans, pulses, baked beans, soya and linseed bread, pears, grapes, nuts.

Medium GI foods – examples include basmati rice, chapatti, couscous, pitta bread rice noodles, potatoes boiled, rye crispbreads, and raisins

High GI foods – examples include baguettes, bagels, rice krispies, rice crackers, pop corn, rice cakes, wholemeal, white bread, jelly beans, glucose tablets.

Practical advice:

High carbohydrate diet – tapering before endurance event

Training diet can be based around low GI foods and moderate GI goods, using high GI immediately after training to help refuel and immediately before or during an event.

Recovery – ensure that you eat carbohydrate and protein food within the first 30 minutes post exercise eg. low fat milk shake drink, or recovery sports drink (contains protein), then try eat carbohydrate rich meal within 2 hours.

Use carbohydrate drinks during an endurance event – can use electrolyte or isotonic  (500-700mls per hour)

Additional info from:

For hot topics in sports nutrition:

http://www.proactivate.co.uk/athletes/hottopics/

For recipes and sports nutrition PDFs to purchase:

http://www.proactivate.co.uk/