title: An investigation into the acute effects of depth jumps on maximal strength performance.
abstract: Research has demonstrated that high-load low-velocity (HLLV) exercises (≥85% 1 repetition maximum [1RM]) increase performance in subsequent low-load high-velocity (LLHV) exercises, when separated by a rest period ≥4 minutes. To date, few studies have investigated LLHV exercises on subsequent HLLV exercises. The purpose of this study was to compare the effects of 2, 4, or 6 depth jumps (DJs) on subsequent 1RM back squat performance. Fourteen subjects (age 22 ± 4 years, height 177 ± 10 cm, body mass 80.3 ± 14.4 kg) completed five 1RM back squat testing sessions, either control, retest, or 1 of 3 interventions (2, 4, or 6 DJs from a height of 33 cm, 4 minutes before the first 1RM attempt), in a counterbalanced order. Intraclass correlation coefficients demonstrated a high test-retest reliability for the 1RMs (r = 0.989, p < 0.001). Repeated-measures analysis of variance with Bonferroni post hoc analysis revealed significantly greater 1RM performance (140.71 ± 35.68 kg: p = 0.004, 140.50 ± 33.77 kg: p < 0.001, 141.43 ± 34.39 kg: p = 0.002, respectively) for each intervention (2, 4, or 6 repetitions, respectively) compared to the control condition (132.43 ± 34.56 kg). No significant differences were found between interventions (p > 0.05). The findings of this investigation demonstrate that the inclusion of 2, 4, or 6 DJs, 4 minutes before a maximal squat, enhances subsequent strength performance.
authors: Manchester City Football Club, Platt Lane, Greater Manchester, United Kingdom.
authors: Nathan
authors: N
authors: Bullock
authors: Paul
authors: P
authors: Comfort
mesh_terms: D000293:Adolescent; D000328:Adult; D056352:Athletes; D054874:Athletic Performance / Q000502:physiology*; D006801:Humans; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D014891:Weight Lifting / Q000502:physiology; D055815:Young Adult