People have been wondering for many years why there are so big differences in strength and circumferences between seemingly similar people. Unfortunately, weight means nothing, it's just a number. Body composition is that element, which informs us about practical transfer of mass on power, strength, speed or endurance. In each case, excess body weight does not foster doing physical activity. In martial arts each additional kilogram (of muscles or fat) makes the competitor fight in higher weight categories (in many organizations one kilogram, literally, determines the category).
In endurance sports, both, muscles and fat disturb in achieving results. During running, swimming, marching, riding a bike or hiking, heart has to do much bigger work, because the competitor is wearing larger load. Therefore, obese people cannot undertake excess physical activity – the circulatory system may not hold out the load. At the same time, you should realize that some amount of body fat is indispensable and we cannot get rid of that (e.g. the synthesis of hormones, including testosterone, transport of vitamins, functioning of nervous system, etc.).
Fatty tissue – it's our reserve, fatty acids stored in other way. They can be placed under the skin and around inner organs (visceral fat).
The norms concerning the amount of body fat for non-training men are following:
For the age group of 18-40 – the non-advised level ranges up to 8% of BF. Low: 8%, moderate: 13%, high: 22%, over 22% - overweight and obesity.
For the age group of 40-65 - the non-advised level ranges up to 10% of BF. Low: 10%, moderate: 18%, high: 25%, over 25% - overweight and obesity.
The norms concerning the amount of body fat for non-training women are following:
For the age group of 18-40 – the non-advised level ranges up to 20% of BF. Low: 20%, moderate: 28%, high: 35%, over 35% - overweight and obesity.
For the age group of 40-65 – the non-advised level ranges up to 20% of BF. Low: 25%, moderate: 32%, high: 38%, over 38% - overweight and obesity.
The norms concerning the amount of body fat for physically active men are following:
For the age group of 18-40 – Low: 5%, moderate: 10%, high: 15%
For the age group of 40-65 - Low: 7%, moderate: 11%, high: 18%
The norms concerning the amount of body fat for physically active women are following:
For the age group of 18-40 – Low: 16%, moderate: 23%, high: 28%
For the age group of 40-65 – Low: 20%, moderate: 27%, high: 33%
(on the basis of the data by Lohman et. Al 1997)
There are many methods allowing to specify the body composition – I will describe them shortly, because this issue is too extended.
At the beginning, however, it's good to deal with bathroom scale which shows fiction. There was a moment in my life, when I had my body fat reduced maximally, a bathroom scale showed me... 20% of fat! The numbers visible on such scale, even the best one, can be put between tales. You can gain better results on some more expensive devices, which also base on the Bioelectrical Impedance Analysis – BIA, although, the result depends on too many factors. There is also a method based on measuring the pocket of fat and circumferences of particular body parts (also with some error), as well as expensive, professional methods, e.g. hydrostatic (underwater weighing) or the Dual-energy X-ray absorptiometry (DXA).
FM – fat mass, the content of fat in the body.
BF – body fat – the percentage of fat in the body.
FFM (fat free mass) – fat-less mass of the body. All the components but fatty tissue.
Lean weight, lean tissue – these phrases refer to the body compounds burning fat, such as muscles, bones, inner organs and connective tissue + indispensable fat. They are the key to “the efficient weight”. The bigger the lean weight, the faster the energy during rest, or even sleep, is burned. That's why it's so important to sustain, or even increase the amount of this body component, especially muscles. Only diet, without any physical activity leads to the decrease of lean weight.
If you introduce drastic changes in your diet (e.g. you will limit the supply of energy to the very scarce level, e.g. 1,000 kcal), you will lead to lower muscle mass and, paradoxically, you will slow down the tempo of burning fat, because you will get rid of the “ovens” (muscle fibres). Women have even bigger problem, as they have less muscle tissue, and more fatty tissue comparing to men.
The same thing concerns limiting strength training and doing more cardio. Aerobic training (especially that of low intensity – 45-65% of HR max), against the theories found in the media and on the Internet, is not the best solution. You have to approach this matter as a whole. Apart from marching, marching with running or running (3-4 x a week, 30-40 minutes each time), you should implement proper strength training (divided or total). With time, you can think of using interval or metabolic training, or crossfit. Strength training will let you keep the muscles and will cause the release of adrenalin / noradrenalin / growth hormone / testosterone / glucagon / cortisol, it will also lower the level of insulin – what will contribute to losing weight. Insulin blocks the reduction of body fat. After eating carbs, it transports them to muscles, but it also increases the synthesis of fat. Additionally, after training (up to 3 hours), the transportation of nutrients is done without insulin, and muscles are more sensitive to it.
In each case, a sports person with the excess amount of body fat profits from losing it – health-wise and visually. A bodybuilder should have low level of body fat. If your waistline is not much smaller than your chest circumference, you must have made a big mistake. The more body fat you lose, the faster, more fit, better at endurance you will be, and your muscles will present better. Even the best muscles covered with a layer of fat, is useless. Additionally, if you reduce body fat , your muscle swill be more sensitive to insulin, what can be beneficial for the future (limited risk of diabetes). Lower body weight fosters limiting the risk of the cardiovascular system.