Nutrition plays a critical role in athletic performance, particularly endurance performance. The human body operates best when it is able to draw on a continuous supply of quality fuel. This supply depends on a balanced diet , supported by sufficient fluid intake to ensure cells are able to function properly.
Avoid foods high in fat and protein, as these take longer to digest. For example fatty meats, french fries, cheeseburgers.
Maintain adequate fluid levels in extended events, such as marathons, continuous replacement is necessary.
Liquid meals (drink with a high carbohydrate content) are recommended if solid meals are difficult to digest. Correctly prepare, they can be an adequate source of nutrition and energy, and contribute significantly to hydration.
It is important to realise that patterns for pre-game eating need to be established over a period of time and new foods should not be added to a diet without a trial period.
Endurance events, particularly in the hot and possibly humid conditions, can have a significant impact on the body’s fuel and fluid supplies.
The aim is to conserve muscle glycogen and maintain blood glucose levels.
Carbohydrate supplementation is needed to avoid glycogen depletion. At exercise intensities above 75% of aerobic capacity, liquid carbohydrate feeding (sports drinks) can delay glycogen depletion by up to 30minutes.
Glycogen supplementation is not needed for low-intensity/short duration events.
Adequate hydration by regular fluid intake must be maintained.
Depending on the sport, some individuals also snack during a break. For example snacking during an event would not be suitable for a marathon runner, compared to Rugby league where an athlete may choose to snack on something simple such as a banana. In some sports is often difficult to eat foods, so these sports may tend to opt for the alternative of sports drinks or liquad meals.
The most important nutritional factor during competition is fluid intake. Dehydration is a concern during any physical activity. Athletes should aim to drink regularly rather than wait until they become thirsty. As a guideline athletes should aim to drink 150-250mls every 15minutes.
In an event less than 30minutes:
Hydrate well before an event.
Fluid taken during the event will not benefit performance as it does not become available to the body within 30mins.
Fluid taken during the event will alleviate a dry mouth and improve perceived exertion.
In events of 30-60minutes duration:
Begin the event well hydrated.
As a general rule: replace fluid every 15mins by drinking 150-250mls of water.
A supplementary source of carbohydrate during exercise has been shown to improve performance in events as short as 60mins.
Post performance nutrition is concerned with the restoration of muscle and liver glycogen stores and the replacement of the fluid and electrolytes that were lost in sweat.
A recovery nutritional plan must aim to:
Replace glycogen stores by eating foods with a high carbohydrate content.
Rehydrate to replace fluid lost during the event. (water or carbohydrate solutions of 5-8 % are recommended as the best choice fluid)
Avoid alcohol because it contributes to dehydration.
Restoration of muscle glycogen stores is enhanced by 3 factors;
The more the glycogen store was depleted, the faster the rate of recovery.
By eating carbohydrates immediately/shortly after exercise.
By ingesting adequate amounts of carbohydrates. Nutritionists recommend 1-1.5 carbohydrate per kilogram of body mass immediately after exercise; the 7-10g carbohydrate per kilogram of body mass in the 24hours after exercise.
Carbohydrate foods with a high glycaemic index should be eaten.