A comparison of neuromechanical adjustments to traditional and eccentric load reduction weighted jump squats.

We compared neuromechanical adjustments between traditional and eccentric load reduction weighted jump squats (WJSs). On separate visits, sixteen strength‐trained men performed three sets of six consecutive WJS with 0% (traditional WJS) or 50% eccentric loading reduction with a mechanical braking unit, while concentric load was set at 30% of 1 RM in all trials. A force platform and a motion capture system were used to assess neuromechanical parameters during eccentric and concentric phases of WJS. Peak power output (+4.5 ± 4.1%; p < 0.001), maximal concentric velocity (+3.2 ± 3.6%; p = 0.004), jump height (+19.6 ± 17.4%; p < 0.001), and reactive strength index (+28.2 ± 20.0%; p < 0.001) were higher when eccentric load was reduced by 50% versus 0%. Compared with traditional jump squat, eccentric phase duration (−6.7 ± 9.9%; p = 0.014), contact time (−6.3 ± 7.2%; p = 0.004), and time to reach peak power output (−7.8 ± 7.6%; p < 0.001) were shorter, while peak vertical force (−15.2 ± 17.5%; p = 0.005) and eccentric mechanical work (−23.9 ± 6.6%; p < 0.001) were lower with eccentric load reduction. Eccentric depth (p = 0.613), eccentric velocity (p = 0.070), amortization time (p = 0.060), maximal concentric force (p = 0.727), and concentric mechanical work (p = 0.396) did not differ significantly between conditions. Compared with traditional isoinertial loading, eccentric load reduction promoted more favorable neuromechanical adjustments during landing and propulsion phases in turn maximizing WJS performance. Highlights: Eccentric load reduction weighted jump squat is a form of plyometric exercise during which a rapid, eccentrically braked downward movement is immediately followed by a maximal effort jump.In strength‐trained men, we found this approach advantageous compared with no braking for potentiating weighted jump squat performance due to more favorable eccentric‐ and concentric‐phase metrics.It is possible that smaller training volumes could be completed in each exercise session without compromising on concentric outputs. Under such circumstances, employing eccentric load reduction weighted jump squat might be a more suitable approach when attempting to execute greater workloads while minimizing fatigue. [ABSTRACT FROM AUTHOR]