title: Acute effects of sled towing on sprint time in male youth of different maturity status.
abstract: The purpose of this study was to investigate the effect of 2.5, 5, 7.5, and 10% body mass load on resisted sled towing 30 meter sprint times in male youth athletes of different maturity status. A total of 35 athletes (19 prepeak-height-velocity (PHV) and 16 mid/post-PHV) sprinted three times in an unloaded and each of the loaded conditions. The pre-PHV athletes were significantly slower (~33%; p < .05) than the more mature athletes across all loads (unloaded, 2.5, 5, 7.5, 10% body mass). Each incremental load (i.e., 2.5% body mass) was found to reduce 30 m sprint times by 3.70% (± 2.59) and 2.45% (± 1.48) for the pre- and mid/post-PHV respectively. The slopes of the pre- (y = 0.09 x + 5.71) and mid/post (y = 0.04 x + 4.38) regression equations were compared and found to be statistically different (p = .004) suggesting that athletes of different maturity status responded differentially to the same relative resisted sprint load. Ten percent body mass load resulted in a reduced sprint time of ~15.8 and ~9.8% for the pre- and mid/post-PHV group, respectively. These results enable predictive equations to be formulated and appropriate resisted sprint loading, based on the intended focus of a session.
authors.affiliation: Sport Performance Research Institute, Auckland University of Technology, Auckland, New Zealand.
authors.forename: Michael Clemens
authors.initials: MC
authors.lastname: Rumpf
authors.forename: John Barry
authors.initials: JB
authors.lastname: Cronin
authors.forename: Ikhwan Nur
authors.initials: IN
authors.lastname: Mohamad
authors.forename: Sharil
authors.initials: S
authors.lastname: Mohamad
authors.forename: Jonathan
authors.initials: J
authors.lastname: Oliver
authors.forename: Michael
authors.initials: M
authors.lastname: Hughes
mesh_terms: D000886:Anthropometry; D054874:Athletic Performance / Q000502:physiology*; D002648:Child; D006801:Humans; D008297:Male; D012420:Running / Q000502:physiology*; D016474:Weight-Bearing