This study aimed to determine whether the provision of jump height feedback (knowledge of result; KR) can increase the performance and the consistency of output variables. Sixteen participants (six women) were randomly tested on four sessions which consisted of (I) squat jump (SJ) without KR, (II) SJ with KR, (III) countermovement jump (CMJ) without KR, and (IV) CMJ with KR. Six maximal jumps (three from a 90º knee angle and three from a self-preferred knee angle) were randomly performed in each session. The provision of KR significantly increased peak force (p=0.046, 1.83%), mean force (p=0.037, 1.45%), peak velocity (p<0.001, 3.71%), mean velocity (p=0.004, 3.44%), peak power (p<0.001, 4.22%) and mean power (p=0.001, 4.69%). A high within-session reliability was observed for all variables (coefficient of variation [CV] ≤ 5.62%, intraclass correlation coefficient [ICC] ≥ 0.95). No systematic differences in reliability were detected between the jumps performed without KR (CV = 3.00 ± 1.38%, ICC = 0.97 ± 0.03) and with KR (CV = 3.04 ± 1.49%, ICC = 0.97 ± 0.04). These results suggest that the provision of jump height feedback during vertical jump testing is effective to enhance vertical jump performance but it does not reduce the variability between jumps.
|Publication status||Accepted/In press - 29 Apr 2020|
Garcia-Ramos, A., Janicijevic, D., Cobo-Font, J., Marcos-Frutos, D., Fernandes, J., Taube, W., & Pérez-Castilla, A. (Accepted/In press). Knowledge of result during vertical jump testing: an effective method to increase the performance but not the consistency of vertical jumps. Sports Biomechanics.