Nutrition and Calorie

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For every physical activity, the body requires energy and the amount depends on the duration and type of activity. Energy is measured in kcal and is obtained from the body stores or the food we eat.

Carefully planned nutrition must provide an energy balance and a nutrient balance.

The nutrients are:

Proteins - essential to growth and repair of muscle and other body tissues
Fats - one source of energy and important in relation to fat soluble vitamins
Carbohydrates - our main source of energy
Minerals - those inorganic elements occurring in the body and which are critical to its normal functions
Vitamins - water and fat soluble vitamins play important roles in many chemical processes in the body
Water - essential to normal body function - as a vehicle for carrying other nutrients and because 60% of the human body is water
Roughage - the fibrous indigestible portion of our diet essential to health of the digestive system


What are the daily energy requirements?

Personal energy requirement = basic energy requirements + extra energy requirements
Basic energy requirements (BER)
For every Kg of body weight 1.3 kcal is required every hour. (An athlete weighing 50Kg would require 1.3 × 24hrs × 50Kg = 1560 kcal/day)


Extra energy requirements (EER)

For each hours training you require an additional 8.5 kcal for each Kg of body weight. (For a two hour training session our 50Kg athlete would require 8.5 × 2hrs × 50Kg = 850 kcal)
An athlete weighing 50Kg who trains for two hours would require an intake of approx. 2410 kcal (BER + EER = 1560 + 850)



Energy Fuel

Like fuel for a car, the energy we need has to be blended. The blend that we require is as follows:
57% Carbohydrates (sugar, sweets, bread, cakes)
30% Fats (dairy products, oil)
13% Protein (eggs, milk, meat, poultry, fish)
The energy yield per gram is as follows: Carbohydrate - 4 kcal, Fats - 9 kcal and Protein - 4 kcal. (Note: 1 calorie = 1 Kcal)
What does a 50 kg athlete require in terms of carbohydrates, fats and protein?
Carbohydrates - 57% of 2410 = 1374 kcal - at 4 kcal per gram = 1374 ÷ 4=343 grams
Fats - 30% of 2410 = 723 kcal - at 9 kcal per gram = 723 ÷ 9 = 80 grams
Protein - 13% of 2410 = 313 kcal - at 4 kcal per gram = 313 ÷ 4=78 grams
Our 50kg athlete requires 343 grams of Carbohydrates, 80 grams of Fat and 78 grams of Protein.


Calories Versus Nutrition

Calories are strictly neutral i.e. from an energy viewpoint it doesn't matter whether you eat a healthy 500 calorie meal (eg. meat, potatoes and vegetables) or two 250-calorie candy bars. Both offer 500 calories worth of energy.
But energy/calories alone will not keep you healthy - the calories you eat must contain sufficient nutrition to maintain your organs and tissue in good health, otherwise your well-being and energy levels will suffer.

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