Energy

Energy is commonly used in relation to being able to complete stressful or demanding tasks, ‘I don’t have the energy for this’ – for example. However energy is required by the body, not just to carry out voluntary movements (walking, running, jumping etc) but also for internal processes (such as breathing, core temperature regulation and digestion). In fact the majority of the energy we consume is actually used up during bodily functions we have no control over; such as breathing, the pumping of blood around the body etc. The amount of energy that is exerted in such activities is described as an individual’s resting metabolic rate (RMR). Depending on the individuals RMR the energy used can be as high as 75% of the amount of energy consumed.

The intake of energy can be measured in joules; however it is common for people to use the term calories in everyday life. They are interchangeable as they both describe the same thing, such as Fahrenheit and Celsius can be used for temperature. The only difference regards to how much energy is measured by each unit. Each is usually measured in kilo’s (thousands), where 1 kcal is equal to between 4.14 and 4.2 kJ. Each individual will require a differing intake level of energy a day to complete their daily tasks. An appreciation of this level is even more crucial to a footballer as they require more energy in accordance with the amount they train. A description of the daily requirements for a regular person is outlined below:

It is very unlikely that you will require any other ages for the individuals you coach but for your reference:

It is the amount of energy consumed, compared to the amount used that determines an individuals weight. Any energy taken on board that is not used will be transformed to fat, and as a result the individual’s weight will increase. If the individual requires more energy than they have consumed or stored up then their body is forced to turn to its fat stores to provide cover for the deficit. This will lower the amount of stored fat in an individual, which in turns will lead to a decrease in body weight*. Therefore a calorie controlled diet is really just watching the amount of energy the individual consumes and uses each day. An increase in body weight of half a kilogram (or one pound) can be experienced if an individual consumes 3500 calories more than they expend.

The body gains energy from carbohydrates, protein, fat and alcohol. Once water is added these components will make up the food. The water content has a direct effect on the energy level as water contains no energy (or calorific) value. Foods such as vegetables have high water content and as a result have low energy levels, while a piece of lard has a low water content and a high energy content. It is possible to use the nutritional labels on packaged foods to view the calorific, however if that is unavailable it is possible to calculate the figure by using the energy breakdown for each component. A breakdown is shown below:

• 1 gram of protein provides 4 kcal
• 1 gram of carbohydrates (starch and sugar based) provides 4 kcal
• 1 gram of alcohol provides 7 kcal (but no additional nutrients)
• 1 gram of fat provides 9 kcal
• Water does not provide any kcal.

* However it must be stated that muscle weighs more than fat. So it may be possible that a person in weight training may experience weight gain rather than weight loss. This is not a reflection on their fat stores but just a reflection that they are increasing their muscle mass.