title: Effect of instantaneous performance feedback during 6 weeks of velocity-based resistance training on sport-specific performance tests.
abstract: The purpose of this study was to investigate the effect of instantaneous performance feedback (peak velocity) provided after each repetition of squat jump exercises over a 6-week training block on sport-specific performance tests. Thirteen professional rugby players were randomly assigned to 1 of 2 groups, feedback (n = 7) and non-feedback (n = 6). Both groups completed a 6-week training program (3 sessions per week) comprising exercises typical of their normal preseason conditioning program. Squat jumps were performed in 2 of the 3 sessions each week during which both groups performed 3 sets of 3 concentric squat jumps using a barbell with an absolute load of 40 kg. Participants in group 1 were given real-time feedback on peak velocity of the squat jump at the completion of each repetition using a linear position transducer and customized software, whereas those in group 2 did not receive any feedback. Pre and posttesting consisted of vertical jump, horizontal jump, and 10-/20-/30-m timed sprints. The relative magnitude (effect size) of the training effects for all performance tests was found to be small (0.18-0.28), except for the 30-m sprint performance, which was moderate (0.46). The probabilities that the use of feedback during squat jump training for 6 weeks was beneficial to increasing performance of sport-specific tests was 45% for vertical jump, 65% for 10-m sprints, 49% for 20-m sprints, 83% for horizontal jump, and 99% for 30-m sprints. In addition to improvements in the performance of sport-specific tests, suggesting the potential for greater adaptation and larger training effects, the provision of feedback may also be used in applications around performance targets and thresholds during training.
authors.affiliation: Sport Performance Research Institute New Zealand, AUT University, Auckland, New Zealand. aaron.randell@aut.ac.nz
authors.forename: Aaron D
authors.initials: AD
authors.lastname: Randell
authors.forename: John B
authors.initials: JB
authors.lastname: Cronin
authors.forename: Justin W L
authors.initials: JW
authors.lastname: Keogh
authors.forename: Nicholas D
authors.initials: ND
authors.lastname: Gill
authors.forename: Murray C
authors.initials: MC
authors.lastname: Pedersen
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D000328:Adult; D054874:Athletic Performance / Q000502:physiology*; D005246:Feedback; D005538:Football / Q000502:physiology*; D006801:Humans; D008297:Male; D053580:Muscle Strength / Q000502:physiology; D018482:Muscle, Skeletal / Q000502:physiology; D055070:Resistance Training / Q000379:methods*; D014891:Weight Lifting / Q000502:physiology; D055815:Young Adult