Abstract
Body composition (BC) and other functional parameters are the main predictors of fitness state in both trained and non-trained subjects. The selected parameters of the BC (% of body fat (%BF), fat free mass (FFM), body cell mass (BCM), extracellular mass (ECM), and ECM/BCM relationship; all these parameters were determined by the whole body multi-frequency bioimpedance method) were determined four times per year in 45 top soccer players (January, March, July and December) (mean age = 21.9+-3.1 years, height = 179.5+-4.0 cm, mass = 75.3+-6.0 kg, %BF = 10.4+-1.7 %, FFM = 67.6+-4.1 kg, ECM/BCM = 0.67+-0.03, VO2peak.kg-1 = 62.7+-3.8 ml.kg-1.min-1, vpeak = 17.7+-0.6 km.h-1 - 1st evaluation).
The %BF was altered during the training year by 9.9+-1.8%, FFM by 3.9+-1.8%, BCM by 8.0+-1.4% and ECM/BCM by 13.8+-2.1%. The increase in body mass during a season is caused by increase in FFM and BCM and reflects qualitative alterations in training; mainly increase of training based on speed and strength.
We may conclude that the parameters that characterize the BC may better reflect the changes in the quality and quantity of the imposed training load and/or training state than the maximal functional variables in highly trained soccer players and thus may be used like a supplementary criterion of imposed training effectivity.