Ten female basketball players served as subjects in order to examine changes in a physical fitness profile during a 22-week official competitive season. Specific explosive type strength training (1-2 sessions per week) was utilized throughout the season. The present findings showed that the entire competitive season led to no systematic changes in the maximum oxygen uptake (from 48.0 +/- 6.6 to 47.0 +/- 6.0 ml.kg-1.min-1), in anthropometric characteristics or in maximal isometric force of the leg extensor muscles (from 2567 +/- 490 to 2622 +/- 747 N). However, significant (p < 0.05) increases occurred during the season both in the average power output during the first 15 s work in an anaerobic jumping test and in the maximal vertical jumping heights in the squat jump (from 21.7 +/- 2.3 to 24.2 +/- 2.4 cm) and in the counter movement jump (from 24.9 +/- 2.6 to 26.3 +/- 2.9 cm). A considerable change occurred also in the shape of the isometric force-time curve of the leg extensor muscles so that the times to produce submaximal force level shortened (p < 0.05). The individual changes during the competitive season both in the power output and in the times of rapid force production correlated negatively (p < 0.05) with the individual initial values recorded before the season. The present findings suggest that the prolonged competitive season in the present female basketball players seemingly placed sufficient demands on the athletes in energy production through aerobic processes to maintain their level of VO2max.(ABSTRACT TRUNCATED AT 250 WORDS)