ACUTE EFFECTS OF VARYING ISOMETRIC MIDTHIGH PULL DURATIONS ON SUBSEQUENT SQUAT JUMP PERFORMANCE

The purpose of this study was to examine the acute effects of perceived maximal isometric midthigh pulls (IMTP) performed for at 3, 5, or 9 seconds on subsequent squat jump (SJ) height performance. Twenty-nine resistance-trained men and women (10 women; mean age 22.8 ± SD 2.9, years, height = 163.9 ± 7.5 cm, body mass = 68.3 kg, 19 men; mean age 23.4 ± SD 3.5 years, height = 175.6 ± 6.9 cm, body mass = 90.0 kg) completed 4 visits (3 experimental and 1 control) in a randomized order, at least 24 hours apart. Participants performed 3 SJ attempts before a single maximal IMTP contraction with 3 minutes of rest in between attempts and 15s, 3 minutes, and 6 minutes after. SJ attempts were performed at a knee angle of 90° and IMTP contractions from a knee angle set at 125-135° and hip angle at 140-150°. Subjects were divided into 2 groups (“high jumpers” and “jumpers”) to determine possible PAPE effects of IMTP contractions on subsequent SJ performance. No significant four-way interaction for condition × time × jumping level × sex (p = 0.468), was found for JH. No significant main effects were found for time (p = 0.945) or condition (p = 0.324). For flight time (FT), there was no significant four-way interaction for condition × time × jumping level × sex (p = 0.363). No significant main effects for time (p = 0.277) or condition were found (p = 0.544). For JH and FT, there were main effects for jumping level (p < 0.001) and sex (p < 0.001). Across all conditions, high jumpers and men demonstrated greater flight times compared to low jumpers and women. In conclusion, a single perceived maximal IMTP contraction activity performed for 3s, 5s, or 9s did not result in statistically significant changes in SJ performance in JH or FT.