title: The acute effects of heavy-load squats and loaded countermovement jumps on sprint performance.
abstract: The purpose of this investigation was to determine whether performing high force or explosive force movements prior to sprinting would improve running speed. Fifteen NCAA Division III football players performed a heavy-load squat (HS), loaded countermovement jump (LCMJ), or control (C) warm-up condition in a counterbalanced randomized order over the course of 3 weeks. The HS protocol consisted of 1 set of 3 repetitions at 90% of the subject's 1 repetition maximum (1RM). The LCMJ protocol was 1 set of 3 repetitions at 30% of the subject's 1RM. At 4 minutes post-warm-up, subjects completed a timed 40-m dash with time measured at 10, 30, and 40 m. The results of the study indicated that when preceded by a set of HS, subjects ran 0.87% faster (p < or = 0.05) in the 40-m dash (5.35 +/- 0.32 vs. 5.30 +/- 0.34 seconds) in comparison to C. No significant differences were observed in the 10-m or 30-m split times between the 3 conditions. The data from this study suggest that an acute bout of low-volume heavy lifting with the lower body may improve 40-m sprint times, but that loaded countermovement jumps appear to have no significant effect.
authors.affiliation: Neuromuscular Laboratory, Department of Health, Leisure & Exercise Science, Appalachian State University, Boone, North Carolina 28608, USA. mcbridejm@appstate.edu
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: McBride
authors.forename: Sophia
authors.initials: S
authors.lastname: Nimphius
authors.forename: Travis M
authors.initials: TM
authors.lastname: Erickson
mesh_terms: D000328:Adult; D018592:Cross-Over Studies; D005538:Football / Q000502:physiology*; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D010806:Physical Education and Training / Q000379:methods*; D012420:Running / Q000502:physiology*; D014891:Weight Lifting / Q000502:physiology