Load-velocity relationships in the back squat: The influence of relative strength

Purpose: The purpose of this study was to investigate the influence of relative strength levels on load-velocity relationships in the back squat (BS). Methods: Healthy male participants (N=18) experienced in the BS performed at relative intensity (as %1RM) intervals of their estimated one-repetition maximum (1RM) up to their maximal effort. Participants were then grouped according to relative strength (1RM/body mass) into weak or strong. A comparison was made using a 2x8 (group by relative intensity) repeated-measures analysis of variance (RM-ANOVA) to identify group effects and intensity zone effect on mean concentric velocity (MCV) of the BS. Results: A significant within-subjects difference was shown between weak vs. strong [F(2.973,57.568) = 298.604, p < .001]. However, contrary to what was hypothesized, weaker participants tended to perform at higher velocities across all intensity zones. Group difference on MCV was different in trend, but not found as significance [F(1,16) = 3.212, p = .092]. Conclusion: Although group difference was not found as significant effect, strength and conditioning professionals should be advised that velocity characteristics of the BS may differ between individuals of different strength levels throughout %1RM ranges. Periodic testing and monitoring of individual athletes may be required in order to capture physical gain due to strength improvement and use of velocity as a tool for training prescription.