Even if you are carrying a few extra pounds

It is a well-known fact - backed up by scientific evidence - that carrying a few extra pounds can affect your performance. It can lead to premature fatigue, increased injury risk and a decreased adherence to training.

Therefore, assessment of body composition has become standard practice in many sports and there are a variety of ways in which to undertake the test.

SO the Rehab Room decided to send former footballer and now self-confessed 'fatty' Ian Clarkson to see what was on offer at Lilleshall Hall. But before we go any father - in true tabloid style - here are a few 'Fat Facts':-

1) Our bodies are made up of different components - one being fat which can be split into essential fat and storage fat. 

2) Essential fat is stored in our vital organs, intestines, muscles and central nervous system and is crucial for normal physiologic functioning. It represents three per cent of total body mass. 

3) In females, essential fat includes additional gender-specific fat, which distinguishes between the body composition of males and females.  It represents nine per cent of total body mass in women, therefore essential fat in women averages 4x that of men.

4) Storage fat surrounds/protects our vital organs and is deposited subcutaneously - we can gain or lose it as it can be used as an energy source.  Storage fat represents 12 per cent body mass in men and 15 in women. 

Therefore, the average male would have total body fat of 15 per cent and the average female 27.

Training and Fat

Footballers tend to have lower than average levels of body fat because the more lean tissue (muscle) a body has, the lower the body fat percentage.  A lower level of body fat is, to a certain point, beneficial to performance as the energy cost of activity will be lower and the ability to maintain core temperature during prolonged exercise will be enhanced.  Body fat is often sports specific - it isn't uncommon for elite male distance runners to have just 3.5% body fat and out-field games players are generally between 8% and 12%. 

One thing that must be remembered is that fat weighs less than muscle.  Therefore it is not sensible to simply use scales to assess changes in body mass as an increase may not be due to increased fat mass.  It is possible to lose fat mass but gain weight due to increased muscle mass, especially in the pre-season period.  So, in order to fully understand any changes in body composition it is crucial to monitor body fat.  In addition, if footballers are trying to reduce their body mass, body fat monitoring is important to ensure no lean mass is lost, as this will detriment performance. 

There are various methods of ascertaining your body fat and one is absolutely foolproof.

Direct measurement of body composition involves the chemical dissolution of fat or dissection of the body and therefore can only be carried out on corpses!

Luckily there are ways round this and we can produce results in less drastic ways.

1) Hydrostatic weighing

Otherwise known as underwater weighing, this method computes body fat percentage from body density and is considered the 'gold standard'.  It involves the individual being submersed in water whilst exhaling as much air as possible.  It is an accurate method of measuring body fat (2-3% error), but the test can be uncomfortable and frightening.

2) Skinfold measurements

This is the most commonly used procedure and is fairly accurate as long the practitioner is competent.  Skinfold measurements are taken at several anatomical sites using calipers - the most common sites are the triceps, biceps, subscapular, suprailiac, abdominal and thigh.  The measurements are either summed and used as a relative fatness indicator or are converted into a percentage.  The accuracy of this method is dependent on the practitioner - a true change in body fat may be missed if the measurements are taken by different people or by the same person with poor technique.  There is also a problem with the equations used to convert to percentage as there is no single equation that applies to the whole athletic world, therefore using the 'sum of skinfolds' may be more appropriate. 

3) Bioelectrical impedance

Electrical currents pass more rapidly through fat-free mass and water than through fat or bone - this fact is used to help calculate body fat.  The subject lies flat with electrodes attached to their wrists and ankles, through which a current is passed and the impedance to the current is determined.  Although this method is quick and easy to administer, the results are often inaccurate.  Small changes in hydration status will affect the accuracy as will a change in skin temperature.  However, even with normal hydration and skin temperature this method tends to over-predict body fat in athletic subjects. 

4) The Bod Pod

This method calculates the difference between the volume of an empty chamber and the volume when a person sits inside to determine body volume.  This figure is used to calculate body density and then body fat percentage.  The Bod Pod is quick, non-invasive and easy to use but, although it seems to be accurate in measuring the volume of inanimate objects, its use for determining the amount of fat in humans is not so readily accepted.  Studies have indicated that it underestimates percent body fat in lean men by three per cent as compared to hydrostatic weighing and overestimates in lean women by up to 14.  There is growing consensus that the Bod Pod does have a gender bias and doesn't work well with lean athletes.

So, if you are a footballer carrying a pound or two you shouldn't be then watch out because there are ways of finding out!