1. Energy Intake and Expenditure

2. Energy Energy is obtained from the foods we eat.
Measure in calories or joules.
As these are both very small they are multiplied by a 1000 and referred to as kilocalories and kilojoules.

3. Sources
The potential fuel sources available to exercising muscles are:
Fats – 1g = 9.0Kcal = 38KJ
Carbohydrate – 1g = 4.0Kcal = 17KJ
Protein – 1g = 4.0Kcal = 17 KJ

4. Protein
May be used during prolonged periods of exercise and towards the latter stages of endurance events like the marathon, particularly if carbohydrate and fat stores have become depleted.

5. When you exercise, your muscles use energy at a rate which is directly proportional to the intensity of your activity.
If this energy is not replaced as it is used up, your muscles will be unable to maintain their rate of work and the intensity of the activity will need to be reduced or stopped.

6. Measuring requirements
Body composition – somatotypes:
Ectomorph
Mesomorph
Endomorph
Lean body mass – includes bone, muscle, water, connective tissue and organ tissue.

7. Percentage body fat Methods of assessing body fat include:
Skinfold analysis
Bioelectrical impedance analysis
Hydrodensitometry

8. Direct and Indirect Calorimetry
Energy expenditure can be assessed by direct or indirect calorimetry (measurement of heat production).

9. Direct Calorimetry
Measures the actual amount of heat produced by the body. It uses an airtight chamber where heat produced by the subject warms water surrounding it.

10. Indirect Calorimetry
Estimates heat production by measuring respiratory gases. The most common technique is through mouthpiece and gas analysis system, with energy consumption calculated from the amount of oxygen consumed.
1 litre of oxygen equates to approximately 4.8Kcal of energy expended.

11. Tasks 1 – perform an internet search of ‘body composition assessment’.
Look at a range of assessment products available and take note of:
Affordability
Ease of application
Suitability for use with athletes

12. 2 – Investigate other measures of energy expenditure including:
Doubly labelled water
Motion analysers