Age-related Differences in Force-velocity Characteristics in Youth Soccer

Although the contribution of anaerobic power to soccer performance has been widely recognized, this parameter of physical fitness has not been well studied in young players. The aim of this study was to investigate the force-velocity (F-v) components of anaerobic power across adolescence. Male adolescent players (N=561; aged 10–22 years), classified into six two-year age groups, all members of competitive soccer clubs, performed the F-v test. The participants performed four sprints, each one lasting 7 seconds, against incremental braking force (2, 3, 4 and 5 kilograms) on a leg cycle ergometer (Ergomedics 874®, Monark, Sweden), interspersed by five-minute recovery periods. Positive correlation between age and theoretical maximal velocity (v0, r=.57, p<.001), theoretical maximal force (F0, r=.53, p<.001), maximal anaerobic power in absolute (Pmax, r=.68, p<.001) and relative-to-body-mass values (rPmax, r=.47, p<.001) was found, while there was negative correlation between age and v0/F0 (r=-.37, p<.001). With regard to Pmax, rPmax, v0 and F0, each age group had a higher score than its younger and a lower score than its older counterparts, while there was no difference between the age group under 18 years (U18), U20 and U22. The v0 to F0 ratio decreased with age, but there was no difference between U16, U18, U20 and U22 with regard to this trait. While our results about the development of anaerobic power across adolescence were in general agreement with previous studies, we identified different patterns of development of the F-v components of muscle power, which was a novel finding.