Associations of maximum and reactive strength indicators with force–velocity profiles obtained from squat jump and countermovement jump

Abstract

Understanding the properties associated with the vertical force–velocity (F–v) profiles is important for maximizing jump performance. The purpose of this study was to evaluate the associations of maximum and reactive strength indicators with the F–v profiles obtained from squat jump (SJ) and countermovement jump (CMJ). On the first day, 20 resistance-trained men underwent measurements for half squat (HSQ) one-repetition maximum (1RM). On the second day, jump performances were measured to calculate the drop jump (DJ) reactive strength index (RSI) and the parameters of F–v profiles (theoretical maximum force [F0], velocity [V0], power [Pmax], and slope of the linear F–v relationship [SFv]) obtained from SJ and CMJ. The DJ RSI was not significantly correlated with any parameter of the vertical F–v profiles, whereas the relative HSQ 1RM was significantly correlated with the SJ F0 (r = 0.508, p = 0.022), CMJ F0 (r = 0.499, p = 0.025), SJ SFv (r = −0.457, p = 0.043), and CMJ Pmax (r = 0.493, p = 0.027). These results suggest that maximum strength is a more important indicator than reactive strength in improving vertical F–v profiles. Furthermore, the importance of maximum strength may vary depending on whether the practitioner wants to maximize the performance of SJ or CMJ.

Can Force-Velocity Profiles Using a Trap-Bar or Body Jump Height Ratio Serve as Alternatives to Those Using a Straight-Bar?

“…Notably, the calculated FVP may differ if different motor tasks are performed. Nishioka and Okada showed that the FVP variables in SJ and CMJ may be incompatible (14). Moreover, Samozino et al's equation was not formulated using a movement task such as a vertical jump, which considered redundancy and coordination (17,18).…”

Relationship between unilateral and bilateral countermovement jump performance and force-velocity-power outcome variables

“…All three variables were moderately correlated to F 0 , but not to the other F-v-P profile parameters. F 0 reflects the maximum concentric force output that the athlete's lower limbs can theoretically produce during ballistic push-off at null velocity (Morin & Samozino, 2016;Nishioka & Okada, 2022;Samozino, et al, 2012). Therefore, the association between CMJ height, UCMJ height and the RSImod BCMJ and F 0 could mean that these variables are indices that evaluate the ability to produce force at lower velocities.…”

“…Through the literature, several studies assessed the association between performance variables and the F-v-P profile. A study done by Nishioka and Okada (2022) evaluated the association between drop jump reactive strength index (DJ RSI) and the parameters of F-v-P profiles obtained from Note. CI -confidence interval; SD -standard deviation; BCMJ -bilateral countermovement jump; UCMJ -unilateral countermovement jump; RSImod -reactive strength index modified; BLD -bilateral deficit; F 0 -maximal theoretical force, v 0 -maximal theoretical velocity; P max -maximal theoretical power; Slope -inclination of the force-velocity regression line; Slope opt -magnitude of the difference between actual and optimal inclinations of force-velocity regression lines.…”

Ballistic Exercise Versus Heavy Resistance Exercise Protocols: Which Resistance Priming Is More Effective for Improving Neuromuscular Performance on the Following Day?

“…For DJ, the contact and take-off were defined as the time points at which the vertical GRF exceeded or decreased below the threshold (i.e., 20 N), respectively. The DJ height was determined using the flight time method ( 26 , 42 ).…”