Relationships between jump and sprint force-velocity profiles and performance

Purpose: The aim of this study was to investigate the associations between matched mechanical variables derived from both vertical and horizontal force-velocity-power (FVP) profiling, and the performance outcome variables within squat jump (SJ) and sprint performance. Methods: 20 elite male academy rugby league players (age 17.6±0.9 years; height 179.9±6.6cm; body mass 91.2±11.8kg) performed two maximal 40m sprints. The sprints were recorded using a radar gun device (Stalker ATS II, Applied Concepts, Dallas, TX, USA), which obtained instantaneous speed-time measurements. In addition, the participants performed two maximal SJ (∼90◦ knee angle) repetitions with these loads: 0kg, 20kg, 40kg, 60kg and 80kg. An Optojump (OptoJump Next Microgate, Bolzano, Italy) was used to record the SJ’s, which provided jump height (cm) for each load. Body mass relative vertical and horizontal mechanical variables (theoretical maximal values of force (F0) (N/kg), velocity (V0) (m/s), power (Pmax) (W/kg)) and the slope of the F-V linear relationship (Sfv) were calculated. Sprint performance was determined from the modelled velocity-time data (2m,5m,10m,20m sprint time (s) and Vmax (m/s). Pearson’s correlation coefficients (r) assessed the relationship between matched vertical and horizontal mechanical variables (F0 vertical & horizontal, v0 vertical & horizontal, Pmax vertical & horizontal and Sfv vertical & horizontal) and SJ and sprint performance. Results: Table 1. shows the correlations coefficient between the sprint and SJ force-velocity profiles and performance variables. There was no significant correlation between vertical and horizontal FVP matched mechanical variables (p > 0.05). The correlations between vertical FVP variables and sprint performance and between horizontal FVP variables and SJ performance failed to reach statistical significance (p > 0.05). Moderate -0.32 to near perfect 1.0 significant correlations (p < 0.05) were found between mechanical and performance variables shifting the importance of separate variables depending on the testing task. Conclusions: The absence of significant correlations between the vertical and horizontal FVP profiles suggests that they provide distinctive information about the athlete’s mechanical variables. The magnitude of the correlations between mechanical variables and sprint performance shifted across the velocity-time curve, therefore performance is determined by separate qualities depending on the distance. Whereas, Pmax reported the greatest correlation with SJ height. Practical Application: To ensure specific, accurate and comprehensive characterisation of athletes’ physical qualities FVP profiles should be determined with exercises maximal mechanically similarity to the targeted performance task. These results will aid practitioners in test selection the prescription and individualisation of training by providing important information as to the most influential variables to develop SJ and sprint performance.

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