CHANGES IN PHYSICAL-FITNESS PROFILE IN FEMALE VOLLEYBALL PLAYERS DURING THE COMPETITIVE SEASON

Nine members of a female volleyball team served as experimental subjects in order to examine changes in a physical fitness profile during the competitive season consisting of a first season (I) for 10 weeks followed by season II for 11 weeks. The entire season was characterized by 4-5 weekly sessions for playing drills and competitive games and by 2-3 weekly sessions for physical conditioning mostly for strength and explosive strength training. The control group consisted of eight other female volleyball players who trained for physical conditioning during the competitive season 1-2 times per week. The present findings showed that the entire competitive season in experimental subjects led to no changes (from 47.3 +/- 1.7 to 48.1 +/- 3.4 ml X kg-1 X min-1) (n.s.) in VO2max but a significant (p < 0.05) decrease took place in average power in a 30 s anaerobic jumping test. Significant increases took place in the maximal vertical jumping heights in the squat (from 30.3 +/- 1.7 to 31.6 +/- 1.3 cm) (p < 0.05) and in the counter movement jump (from 32.8 +/- 1.6 to 34.3 +/- 1.3 cm) (p < 0.05) as well as in the spike and block jumps (p < 0.05) during competitive season I. When strength training was terminated at the middle of season Il for 5 weeks, significant decreases took place both in maximal isometric leg extension strength (from 2944 +/- 578 to 2766 +/- 318 N) (p < 0.05), in the squat (to 30.3 +/- 1.3 cm) (p < 0.05), in the counter-movement jump (to 32.2 +/- 1.5 cm) (p < 0.05) and in the maximal explosive strength capacity of the upper body extremity (and trunk) muscles (p < 0.01). The changes in maximal strength were correlated (r = 90; p < 0.01) with the changes in the maximal vertical jump performances. The control group demonstrated only slight changes in physical performance characteristics during the entire season. The present findings suggest that in order to maintain the level of explosive strength performance characteristics in female volleyball players the magnitude of both strength and explosive strength training stimuli should be given careful attention during the entire course of the competitive season.