Introduction: The infl uence of exercise in trained subjects has beneficial effects in the physical fi tness and body composition; however, detraining has an unfavorable effect in all of them.
Objective: The current study was designed to ascertain the infl uence of a six week-detraining period on body composition in both well-trained young soccer players (GE, n = 43) and sedentary male adolescents (GC, n = 10).
Methods: Forty-three well-trained soccer players and ten sedentary adolescents accepted to participate in the study. Body composition measurements included fat mass and skeletal muscle mass (SMM), which were estimated by anthropometry. In addition, total body water (TBW), intracellular water (ICW) and extracellular water (ECW) were assessed by bioelectrical impedance analysis (BIA) at the end of training and after detraining periods.
Results: After the six-week-detraining period, signifi cant increments were found in TBW (35.5 ± 5.2 vs.36.7 ± 4.9 kg; p < 0.001), ICW (14.2 ± 1.8 vs. 14.8 ± 1.6 kg; p < 0.001) and ECW (21.5 ± 3.6 vs. 22.0 ± 3.4 kg; p < 0.001) in soccer players. Conversely, no changes were observed in ECW/TBW (0.4 ± 0.02 vs. 0.4 ± 0.02; p > 0.05) and ICW/TBW (0.6 ± 0.02 vs. 0.597 ± 0.02; p > 0.05) ratios. Finally, fat mass was significantly increased (8.6 ± 3.2 vs. 8.95 ± 3.1 kg; p < 0.01) in the detrained group. No signifi cant changes were found in SMM (21.2 ± 2.5 vs. 22.22 ± 2.8 kg, p > 0.05).
Conclusions: After a six-week detraining period, body composition changed signifi cantly in well-trained adolescents. The main fi nding of this study was that increments of TBW and water distribution were observed in the soccer group, which refl ects an increase of fat free mass compartment. The physiological importance of this miss-adaptation needs to be elucidated in future research. Further studies on this topic are still required to assess its impact on physical performance.
Keywords: Body composition.; Anthropometry.; Bioelectrical impedance analysis; Detraining.