Abstract des Autors

The purpose of the present study was to investigate the acute effect of drop jumping on throwing performance. Eight men and 8 women, moderately trained subjects with basic shot put skills, performed 3 squat underhand front shot throws after a short standard warm-up. Three minutes later they performed 5 maximal consecutive drop jumps from 40 cm. Immediately after the drop jumps, they repeated the squat underhand front shot throws. On another day, their 6 repetition maximum (RM) muscular strength in leg press was assessed. Muscle biopsies were also obtained from vastus lateralis for the determination of fiber-type composition and fiber cross-sectional area. Throwing performance was significantly increased after drop jumping (8.25 ± 1.1 m vs. 8.63 ± 1.3 m, p < 0.01). The percentage of type II muscle fiber area was significantly related to the increase in throwing performance after drop jumping (r = 0.76, p < 0.01). The increase in throwing performance was significant in men (8.94 ± 1 m vs. 9.60 ± 0.9 m, p < 0.01) but not in women (7.56 ± 1 m vs. 7.67 ± 0.9 m, ns). Of note, the percentage of type II fiber area was higher in men than in women (M: 66.4 ± 13%, F: 50.2 ± 15%, p < 0.01). Leg press strength (6RM) was moderately related to the increase in throwing performance after drop jumping (r = 0.50, p < 0.05). These results suggest that drop jumping just before a throwing action induces an increase in performance in subjects with a high percentage of type II muscle fiber area and (to a lesser degree) in subjects with enhanced muscular strength. Verf.-Referat