Nutrition Apple

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. Glycogen is the main source of fuel used by the muscles to enable you to undertake both aerobic and anaerobic exercise. If you train with low glycogen stores, you will feel constantly tired, training performance will be lower and you will be more prone to injury and illness.
A calorie (cal) is the amount of heat energy required 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

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
  • fiber - 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


What types of fat are there?

The nature of the fat depends on the type of fatty acids that make up the triglycerides. All fats contain both saturated and unsaturated fatty acids but are usually described as 'saturated' or 'unsaturated' according to the proportion of fatty acids present. Saturated fats are generally solid at room temperature and tend to be animal fats. Unsaturated fats are liquid at room temperature and are usually vegetable fats - there are exceptions e.g. palm oil, a vegetable oil that contains a high percentage of saturated fatty acids.



Sunflower oil


Olive Oil


Rice Oil




Rapeseed Oil


Oily fish - Sardines


What types of carbohydrates are there?

There are two types of carbohydrates - starchy (complex) carbohydrates and simple sugars. The simple sugar's are found in confectionery, muesli bars, cakes and biscuits, cereals, puddings, soft drinks and juices and jam and honey but they also contain fat. Starchy carbohydrates are found in potatoes, rice, bread, wholegrain cereals, semi skimmed milk, yoghurt, fruit, vegetables, beans and pulses. Both types effectively replace muscle glycogen. The starchy carbohydrates are the ones that have all the vitamins and minerals in them as well as protein. They are also low in fat as long as you do not slap on loads of butter and fatty sauces. The starchy foods are much more bulky so there can be a problem in actually eating that amount of food so supplementing with simple sugar alternatives is necessary.

Eating and Competition

What you eat on a day-to-day basis is extremely important for training. Your diet will affect how fast and how well you progress, and how soon you reach competitive standard. Once you are ready to compete, you will have a new concern: your competition diet. Is it important? What should you eat before your competition? When is the best time to eat? How much should you eat? Should you be eating during the event? In addition, what can you eat between heats or matches?.

What do I need to do?

Calculate your daily basic and extra requirements, monitor your daily intake (especially your carbohydrates) and then adjust your diet to meet your daily requirements. A good balanced diet should provide you with the required nutrients but does needs to be monitored. The simplest way to monitor the 'energy balance' is to keep a regular check of your weight.

Key factors in your training diet

Each day have three main meals and two to three snacks. All meals should contain both carbohydrate and protein - 20 to 30 grams worth of protein with each main meal and 10 to 20 grams with each snack.
The amount of carbohydrate will vary greatly, mainly depending on your workload. It may be in the region of 40 to 60 grams for main meals and 20 to 30 grams for snacks. If you are training hard and possibly doing multiple daily sessions, the recovery meal is critical. Have 1grm of carbohydrate per kg of body weight and about 30 grams of protein. Have a drink (e.g. a recovery drink or a pint of skimmed milk) and a banana immediately post-training (this provides about 10 grams of protein and 30 grams of carbohydrate) followed within about 45 minutes with more substantial food such as beans on toast and tuna.
Always try to eat at least five pieces of fruit per day. Skimmed milk is a great protein food and provides critical minerals, such as calcium and phosphorous.

Food Composition Tables

Food composition tables are widely used to assess nutrient and energy intakes, and to plan meals. The composition of food can vary widely, depending, among other factors, on the variety of plant or animal, on growing and feeding conditions and, for some foods, on freshness. Tables are based on average values from a number of samples analysed in the laboratory and therefore only provide a rough guide.
Vitamin sources:
Vitamin A (fat-soluble)

  • Sources: Dairy products, eggs, liver. Can be converted by the body from the beta-carotene found in green vegetables, carrots and liver.

Vitamin B1 (thiamine) (water-soluble)

  • Sources: Yeast, egg yolk, liver, wheat germ, nuts, red meat and cereals

Vitamin B2 (riboflavin) (water-soluble)

  • Sources: Dairy products, liver, vegetables, eggs, cereals, fruit, yeast

Vitamin B12 (water-soluble)

  • Sources: Liver, red meat, dairy products and fish

Vitamin C (ascorbic acid) (water-soluble)

  • Sources: Green vegetables and fruit

Vitamin D (fat-soluble)

  • Sources: Fish liver oils, dairy produce. Vitamin D is formed in the skin when it is exposed to sunlight

Vitamin E (fat-soluble)

  • Sources: Pure vegetable oils; wheat germ, whole meal bread and cereals, egg yolk, nuts sunflower seeds

Vitamin K (fat-soluble)

  • Sources: Green vegetables