Diet therapy

Exercise and increased antioxidant requirements

To provide additional energy needed during exercise, the oxygen used in the exercising muscles increase by about 10-20%.

A bi-product of the increased oxygen use is increased production of free radicals and therefore increased oxidative stress.

Sources of oxidative stress

As well as exercise, environmental factors can initiate free radical reactions. Some examples are UV light, x-rays, polycyclic aromatic hydrocarbons, smoking and fast foods.

Our modern diet has a large effect upon free radical formation. We eat more fatty food, we fry our foods and refined food products have lower levels of antioxidants and higher levels of preservatives than ever before.

Although active people may not monitor their weight and their current exercise regimens may tend to help with reduction in fat mass that aids the increase of lean muscle mass, they can still be at risk of oxidative stress.

It is still vital for our athletes to consider the type of foods being consumed, if not for the health benefits to be enjoyed later in life, then for the success that arises in those who carefully consider the foods they consume in the off-season as well as during training and competition.

To gain the competitive edge use the appropriate carbohydrate containing foods.

Fruits and vegetables

  • Contain a range of antioxidants.
  • Processing and cooking does not usually reduce antioxidant content; in fact it often makes carotenes more easily absorbed!
  • Colourful vegetables tend to be rich in antioxidants, especially if the colour on the skin follows right through into the flesh of the fruit or vegetables (Eg blackcurrants, blueberries, strawberries).

Breads and cereals

  • Antioxidants are most abundant in the germ and bran of grains, therefore whole grains and whole grain products are best.
  • However as you get closer to race days and your overall carbohydrate intake increases you may need to reduce some of the fibre in your diet temporarily in order to prevent gastrointestinal upset

If you would like to check your intake of key nutrients and receive more advice regarding sports nutrition for improved performance and energy levels contact us today.

About the author View all

Lea Stening

Lea is one of New Zealand’s leading paediatric dietitians and also specialises in Sports Nutrition. She has specialised in Paediatric Nutrition for 31 years and in 1985 was the first paediatric dietitian to enter private practice in New Zealand. Lea helps families through her private consultations, public lectures, newspaper and magazine articles as well as television and radio interviews. Read more »

View all posts by Lea Stening »


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