Fat mass of runner
In running, the weight is very important because the extra kgs decrease tremendously the performances (Ref.). This is verified with the champions of marathon who are very light (58 kg on average).
The fat mass of each person is very variable. It varies normally from 13 to 21% for men and from 18 to 26% for women, and increases with the age.
It is impossible to lower this percentage under 4% without risk for the health. Furthermore, this fat mass is important for people living in cold countries because it slows down the thermic exchanges between the outside and the inside of the body in which the temperature must be kept constant.
However, it is possible to limit the body mass by controlling this fat mass, lowering it to 6% for men and 13% for women.
To do it, it is necessary to do long efforts not very intense and to act on the food (Ref.).
So, by controlling the fat mass, it is possible to lose about 10% of weight and to gain consequently 10% of power (Ref.).
Calculation of ideal weight
Attention ! Most of personal scales analysing the fat mass are not capable to give correct measures !