Weight: The Percentage Factor

There is no doubt that the single most effective way to improve performance - in the short term - is loss of weight, if of course there is an excess of body fat.  It is this factor alone that is central to the issue when discussing weight loss - and not the overall weight of the athlete.

The only problem - in my experience – has been when restrictive diets have been undertaken by juniors under 18-20 years of age, when their bodies are still growing.  This is a more delicate area and only professional dieticians should have a say within this age group.

Commonsense must always prevail when discussing weight reduction for any athlete who is on a demanding training regime, if an athlete is to maximize their performance it is essential that they adopt a sensible approach to a healthy-eating regime as part of an overall training package.

So how can an athlete determine if they are a case for weight loss based on fat percentage?

Unfortunately people cannot tell by simply weighing themselves and looking at a height-weight chart what their % body fat is, or if they are overweight or underweight.  Height-weight charts are based on averages, and only about 20% of the population conforms to the averages on the charts.  The charts make no allowance for muscle development, and most people don’t really know what their frame size is.  The only way to determine the amount of fat on an athlete’s body is by actual measurement of their body fat.

A normal healthy person – not athlete - should fall within the following bands of fat percentage:

For men up to about age 30, 9 – 15% is good.  From age 30–50, 11 to 17% is a good range, and from age 50 and up, 12 – 19% is about right.

For women, the range up to age 30 is 14 to 21%, from 30-50, 15 to 23% and from 50 up it is 16 to 25%.

The reason I say for a normal healthy person, is that athletes vary appreciably from these figures and depending on what level the athlete is at will vary even more.  The various disciplines within athletics allow for more variation, and not always lower!  Olympic throwers usually come in around the 30% mark, whereas Olympic swimmers can be in the 9–12% band.  Rowers who work from a power base can hover around the 15% mark, whereas the running disciplines start to plunge with elite male marathon and middle distance runners, dipping below the 5% figure.

So the variation is tremendous and it calls for expert advice on where each individual athlete should be, at that moment of time in their career, taking into account age, sex, ability and sport discipline.

Measuring body fat also has its variations.  The most accurate way is obtained by underwater weighing, but considering the equipment required, only a few Universities and the like have this facility.  Most coaches and health professionals use the Skin Fold Caliper method which is very accurate.  Body Fat Monitors (BFM) are becoming increasingly popular but come in at around £100 for a good set of scales.  The more you pay the more accurate they become.

If you don’t want to be too precise then the BMI method is fine, just follow the formula at the end of this article and see where you fit in.  This method does not take into account those larger athletes who are very fit; rugby players, weight lifters, etc.

Finally if you are ace with a calculator you could always try the Stillman Table, a tried and tested formula for checking your height/weight ratio.

It is worked on the average man principle:

The average man is allocated 110 lbs (50 kg) for the first 5 feet (1.524 m) in height.  Thereafter, he is allocated 5½ lbs (2.495 kg) for every additional inch (0.025 m) in height.

Thus, a man 6 feet tall (1.829 m) would be allocated 110 lbs (50 kg) plus 12 x 5½ lbs (2.495 kg), which comes to 176 lbs or 12 st. 8 lbs (80 kg).

Females are allocated 100 lbs (45 kg) for the first 5 feet (1.524 m) and 5lbs (2.268 kg) for every inch thereafter.  Therefore a woman who is 5 ft 6 ins (1.676 m) tall would be given 100 lbs plus 6 x 5 lbs, which totals 130 lbs or 9 st. 4 lbs (59 kg).

These figures are based on calculations for healthy non-active people, and athletes who run middle-distance (800m - 10K) need to be around 12 per cent lighter.  Longer distance runners (10 miles onwards) need to be looking at being 15 per cent lighter.

So if all that confuses you then simply go and see your club coach and see if he will do a fat percentage check.  Having established a percentage figure, what you do with it is a whole new ball game, and for another article.

Norman Matthews

Or you can forget the calculations and use the pre-set tables below; sorry it’s in old money!  But considering that vets rule on race numbers I am all for democracy.

Body weight in pounds according to height and body mass index.