Cardiorespiratory power across adolescence in male soccer players.

Despite the recognition of the beneficial role of cardiorespiratory power (CRP) for health and sport performance, the development of this physical fitness parameter in adolescent soccer players was not well studied. Aim of this cross-sectional study was to investigate the effect of age on CRP of adolescent soccer players, the influence of anthropometric characteristics and body composition on it, and to establish normative data. Male adolescent (N=274; aged 12.07-20.98 y), classified in nine one-year age-groups, child (N=12, aged 7.71-11.8 y) and adult players (N=22; aged 21.12-31.59 y), all members of competitive soccer clubs, were examined for anthropometric characteristics and body composition and they performed Physical Working Capacity in heart rate 170 test (PWC170) on cycle ergometer. Analysis of variance revealed significant difference between age groups with respect to PWC170 in absolute (F10.297 = 29.58, P < 0.001, eta2 = 0.5), relative to body mass (F10.297 = 5.28, P < 0.001, eta2 = 0.15) and relative to fat free mass values (F10.297 = 4.98, P < 0.001, eta12 = 0.14). In addition, age was in positive association with these parameters (r = 0.6, P < 0.001, r = 0.24, P < 0.001 and r = 0.23, P < 0.001, correspondingly). The main finding of this study was that CRP increased during developmental period in soccer players, even when it was adjusted to body mass or FFM, which increased during development. This documentation of the development of CRP provided useful tool for coaches and fitness trainers in order to apply optimal exercise interventions for health and performance.