Loturco, Irineu; McGuigan, Michael R.; Freitas, Tomás T.; Bishop, Chris; Zabaloy, Santiago; Mercer, Valter P.; Moura, Túlio B.M.A.; Arruda, Ademir F.S.; Ramos, Maurício S.; Pereira, Lucas A.; Pareja-Blanco, Fernando.

Journal of Strength and Conditioning Research 37(5):p 1052-1056, May 2023. | DOI: 10.1519/JSC.0000000000004382

PURPOSE:

Tto compare the peak force (PF), peak power (PP), and peak velocity (PV) outputs produced during half-squat (HS) and jump squat (JS) exercises executed at 20, 40, 60, and 80% of 1-repetition maximum (1-RM) in the HS (HS 1-RM) and to compute and compare the strength deficit (SDef) achieved in these exercises across these loads.

PROCEDURES:

Twenty-four national rugby union players age 25.7 ± 3.6 years performed HS 1-RM and a progressive loading test in the HS and JS exercises. The PF, PP, and PV values were obtained in all loads for both exercises, and the SDef was calculated as the percentage difference between the PF at distinct relative intensities and the PF at HS 1RM. The differences in HS and JS variables were determined using an analysis of variance with repeated measures.

CONCLUSIONS:

o Higher PF, PP, and PV outputs were generated in the JS in comparison with the HS exercise.

o The SDef magnitudes were significantly lower in the JS for all loading conditions.

o The differences in SDef and consequently the PF, PP, and PV decreased progressively with increasing load.

o Overall, the loaded JS exhibited increased levels of PF, PP, and PV and reduced levels of SDef when compared to the traditional HS performed across a range of loads.

o The JS is indicated to reduce the SDef and improve the athletes' ability to apply force at higher velocities, but with heavier loads ≥80% HS 1RM its potential advantages and effectiveness may be seriously compromised.

IN PLAN ENGLISH:

Based on the laws of gravity on Earth, the lighter the resistance used, the faster it can be moved relative to one’s 1-RM.

Alternatively, the heavier the resistance used, the slower it will move relative to one’s 1-RM, however more total muscle fibers/motor units are activated over the length of the event.