Improved Maximum Strength, Vertical Jump and Sprint Performance after 8 Weeks of Jump Squat Training with Individualized Loads

The purpose of the study was to determine the effects of 8 weeks of jump squat training on isometric half squat maximal force production (Fmax) and rate of force development over 100ms (RFD100), countermovement jump (CMJ) and squat jump (SJ) height, and 50 m sprint time in moderately trained men. Sixty eight subjects (similar to 21 years, similar to 180 cm, similar to 75 kg) were divided into experimental (EXP; n = 36) and control (CON, n = 32) groups. Tests were completed pre-, mid- and post-training. EXP performed jump squat training 3 times per week using loads that allowed all repetitions to be performed with = 90% of maximum average power output (13 sessions with 4 sets of 8 repetitions and 13 sessions with 8 sets of 4 repetitions). Subjects were given real-time feedback for every repetition during the training sessions. Significant improvements in Fmax from pre- to mid- (. similar to 14%, p<0.001), and from mid- to post-training (Delta similar to 4%, p < 0.001) in EXP were observed. In CON significantly enhanced Fmax from pre- to mid-training (Delta similar to 3.5%, p < 0.05) was recorded, but no other significant changes were observed in any other test. In RFD100 significant improvements from pre- to mid-training (Delta similar to 27%, p < 0.001), as well as from mid- to post-training (Delta similar to 17%, p < 0.01) were observed. CMJ and SJ height were significantly enhanced from pre- to mid-training (Delta similar to 10%, similar to 15%, respectively, p < 0.001) but no further changes occurred from mid- to post-training. Significant improvements in 50 m sprint time from pre- to mid- training (Delta -1%, p < 0.05), and from mid- to post-training (Delta -1.9%, p < 0.001) in EXP were observed. Furthermore, percent changes in EXP were greater than changes in CON during training. It appears that using jump squats with loads that allow repetitions to be performed = 90% of maximum average power output can simultaneously improve several different athletic performance tasks in the short-term.