title: Are acute effects of maximal dynamic contractions on upper-body ballistic performance load specific?
abstract: This study investigated the acute effects of upper-body maximal dynamic contractions on maximal throwing speed with 0.55- and 4-kg medicine balls. It was hypothesized that heavy preloading would transiently improve throwing performance only when overcoming the heavier of the two loads. Twenty-three male volunteers were randomly allocated into experimental (n = 11) and control (n = 12) groups. Both groups performed initial and final seated medicine ball throws from the chest, and the maximal medicine ball speed was measured by means of a radar gun. Between the two measurements, the control group rested passively for 15 minutes, and the experimental group performed three sets of three-repetition maximum bench presses. For the 0.55-kg load, a 2 x 2 repeated-measures analysis of variance revealed no significant effect of time x group interaction (p = 0.22), as well as no significant time (p = 0.22) or group (p = 0.72) effects. In contrast, for the 4-kg load, a significant time x group interaction (p = 0.004) and a significant time (p = 0.035) but not group (p = 0.77) effect were observed. Analysis of simple main effects revealed that the experimental group significantly (8.3%; p < 0.01) improved maximal throwing speed with the 4-kg load. These results support our research hypothesis and suggest that the acute effects of heavy preloading on upper-body ballistic performance might be load specific. In a practical sense, our findings suggest that the use of upper-body heavy resistance exercise before ballistic throwing movements against moderate external loads might be an efficient training strategy for improving an athlete's upper-body explosive performance.
authors.affiliation: School of Kinesiology, University of Zagreb, Croatia. gmarkov@kif.hr
authors.forename: Goran
authors.initials: G
authors.lastname: Markovic
authors.forename: Sanja
authors.initials: S
authors.lastname: Simek
authors.forename: Asim
authors.initials: A
authors.lastname: Bradic
mesh_terms: D000328:Adult; D044709:Forensic Ballistics; D006801:Humans; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology; D055070:Resistance Training / Q000379:methods*; D014891:Weight Lifting / Q000502:physiology*; D016474:Weight-Bearing / Q000502:physiology*