For every physical activity, the body requires energy. The amount of required energy depends on the duration and type of activity. Energy is measured in kcal and it is obtained either from body stores or the food we consume. Glycogen is the main source of fuel used by muscles to enable you to undertake both aerobic and anaerobic exercises. If you train with low glycogen stores you will feel constantly tired, your training performance will be lower and you will be more prone to injury and illness.

A calorie (cal) is the amount of heat the energy requires to raise the temperature of 1g of water 1°C from 14° to 15°C. A kilocalorie (kcal) is the amount of heat required to raise the temperature of 1000g of water 1°C.

Nutrient Balance

A carefully planned nutrition must provide energy and nutrient balance. The necessary nutrients are:

• Proteins - essential to growth and repair of muscle and other body tissues.
• Fats - a source of energy important in relation to fat soluble vitamins.
• Carbohydrates - a main source of energy
• Minerals - inorganic elements occurring in the body 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 ; a vehicle for carrying other nutrients; 60% of the human body is water.
• Roughage - the fibrous indigestible portion of our diet essential to health of the digestive system.

Daily Energy Requirements

personal energy requirement = basic energy requirements + extra energy requirements.

Basic Energy Requirements

For every Kg or 2.2 Lbs (pounds) of body weight, 1.3 kcal of energy is required every hour.

Example: An athlete weighing 110 Lbs (50Kg) would require 1.3 * 24hrs * 50Kg = 1560 kcal/day.

Extra Energy Requirements

For each hour of training, you require 8.5 kcal for each Kg of your body weight.

Example: For a two hour training session our 110 Lbs (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 (1560 + 850)