ABSTRACT
This study explored the influence of different take-off thresholds on the reliability and magnitude of countermovement jump (CMJ) performance variables. Twenty-three men were tested on two separate sessions. CMJ performance variables were obtained against three external loads (0.5–30-60 kg) using three take-off thresholds: 10 N (arbitrary value of 10 N), 5SD (mean value plus 5 standard deviations of the vertical force recorded during the flight phase), and PRF (peak difference between the vertical force trace and 0 N during the flight phase). No significant differences in reliability were observed between the three thresholds (CV and ICC values of one threshold were within 95% CI of the other thresholds). The magnitude of the variables generally differed between the 10 N threshold and the 5SD and PRF thresholds (P < .05), but not between the 5SD and PRF thresholds (P > .05). These results demonstrate that the take-off threshold influences the magnitude of CMJ performance variables but not their reliability.
Acknowledgments
We would like to thank all the volunteers who selflessly participated in the study. This study was funded by the Spanish Ministry of Science and Innovation (PID2019-110074GB-I00/SRA (State Research Agengy)/10.13039/501100011033).
Declaration of interests
The authors report no conflict of interest.