Abstract

The aim of the study was to estimate vertical jumping performance in orienteers of various age and both sexes. The study embraced 92 orienteers of national level. According to age (years) and gender (males, M; females, F), six groups of athletes were singled out: F15-17 (n = 19), F18-20 (n = 9), F > 21 (n = 4), M15-17 (n = 21), M18-20 (n = 18), and M>21 (n = 21). After a standard warm-up, subjects performed maximal intensity vertical jumps on the contact mat sized 60x60 cm. After orienteers made jumps with and without arm swing (3 attempts each), all-out vertical jumps for 60 s with a shock-absorbing squat to 90° knee angle, arms akimbo, were performed. The jump height was measured according to C. Bosco et al., using a flight-phase time as a sole indicator. There were no statistically significant differences in the height of the single vertical jump between age groups, irrespectively of gender. However, statistically significant differences were observed in the height of the single vertical jump at all age groups in respect to gender. The comparison of vertical jumps performed by females with and without arm swing revealed statistically significant difference only between F15-17 and F18-20 groups, while the difference in jump height between two modes was statistically significant in male orienteers of all age groups (p < 0.001). F15-17 and F18-20 groups differed in respect to fatigue index during 60 sec test (p < 0.05). The different fatigue index was observed in respect to gender between orienteering athletes aged 15-17 years. Conclusions: Relative power of the leg extensors are related to gender but not age in young orienteers. In respect to jumping performance, young orienteers are more similar to track-and field sprinters rather than distance runners. In all age and gender groups, jump height was increased when arm swing was allowed. Anaerobic lactic capacity (endurance) of leg extensors (average relative power, or sum of the jump heights during 60-second vertical jump test) in female orienteers was lower in teenage groups when compared to young adults, but no relation of anaerobic lactic capacity in respect to age was observed in males. Verf.-Referat