Methods to calculate lower-body stretch-shortening cycle utilization in the vertical jump: Which is the best for athletes of different sports?

Purpose. - This study aimed to verify if different stretch-shortening cycle (SSC) methods, obtained by the vertical jump test, present the same characteristics through consistency and agreement analysis, and to compare the SSC methods between athletes of different sports. Summary of facts and results. - Three hundred and forty-one male athletes of three sports groups (combat sports, team sports, and runners) participated in this study. Athletes performed the countermovement jump and squat jump tests to identify the SSC using three methods: reactive strength index (RSI), pre-stretch augmentation percentage (PSA), and eccentric utilization ratio (EUR). The results demonstrated very large correlations between the methods for jump height (r = 0.96-0.98) and power output (r = 0.95-0.98), almost perfect agreement for jump height (k = 0.86-0.91) and substantial to almost perfect agreement for power output (k = 0.77-0.92). The RSI, PSA, and EUR were higher in team sports than combat sports for jump height (P = 0.006, P = 0.008, P = 0.007, respectively), EUR was higher for team sports than combat sports for power output (P = 0.041). Conclusion. - The methods of SSC are strongly correlated and present excellent agreement. Team sports athletes presented greater use of SSC compared to combat sports regardless of the method. (c) 2023 Elsevier Masson SAS. All rights reserved.