Nutrition and Exercise

Written on the 19 September 2014 by Active Body Physiotherapy

Nutrition for exercise is an ongoing balance and should be planned out, well in advance, with a structured approach. We will target the event day pre-race nutrition and recovery. These are the general guidelines that will need to be tailored to your specific requirements of your event and daily energy requirements.  These two areas of nutrition, if planned and practiced before an event, will enable peak performance and improvement for the future.
Before exercise (on the day)

Nutrition before exercise should be planned and consumed to make the exercise event comfortable. It should provide you with the correct energy and fluid requirements to complete the event (with the exception of an endurance event that may last hours and require regular eating and drinking throughout). The meal(s) prior to exercise should be eaten long enough prior to be absorbed to offer you the energy requirements you require. Certain foods take longer to digest which can create some stomach issue whilst exercising.

Pre event meals are often consumed 3-4 hours before. This meal is often a larger meal that is comprised of higher carbohydrate content with low fat and fibre content, also consume fluids as this all aids with digestion. A smaller snack that is light and easily digestible should be consumed 1-2 hours pre-event.

Post Exercise
Recovery nutrition is all about preparing your body for your next bout of exercise. It is especially important for athletes who are exercising twice per day, or have a short turn around between events. The basic principles of recovery are to replenish fuel stores in the way of carbohydrates, which are converted to glycogen in the muscle and liver secondly is to replace fluid lost during the bout of exercise and thirdly the building process of repair and adapting to the stress of the training/exercise.

There is a small window of opportunity where food and fluid consumed is absorbed quicker into the body and prepares us for the next exercise. This window is generally accepted as about 60 minutes; however there are some sources that quote 90 minutes.

Replacing the used energy is essential; our energy sources convert into glycogen and replace the liver and muscle stores. A recovery meal or snack should consume between 1-1.2g of carbohydrate per kg of body weight.

Rehydration following exercise can be vital as fluid losses of 2% can adversely affect performance. Replacing fluids should be achieved in the 4-6 hours following exercise, achieving 125-150% of the perceived fluid loss. Be sure to include small amounts of sodium as this will aid in the replenishment of electrolytes (50-80mmol/L is recommended), the addition of sodium will help to reduce urine output. An easy way to estimate your fluid loss is to weigh yourself before and after exercise, the loss in weight is a quick way to work out the amount of fluid lost. The reason we need to consume more fluid is because of the progressive loss through sweating following the end of the activity and the continuous urine output.

Adaptation to exercise, this is important in the building of new muscle following an intense session of exercise where muscle is broken down.  Early intake is important for the regeneration of new proteins (the building material for muscle and tissue). In the recovery window 15-25g of protein should be consumed.

Nutrition and exercise is a very specific and individualised area, this article is designed for a generalised idea on what the body requires pre and post exercise for optimum performance and recovery requirements of exercising population. For a specific nutrition program, it is best to seek professional advice from a Nutritionist/Dietician.

Jake Mcloon
Physiotherapist
M.PHTY;B.ExSc