AbstractIt is unclear if increases in one repetition maximum (1-RM) in quarter squats result in higher gains compared to full depth squats in isometric force production and vertical jump performance. The aim of the research projects was to compare the effects of different squat variants on the development of 1-RM and their transfer effects to Countermovement (CMJ) and Squat Jump (SJ) height, maximal voluntary contraction (MVC) and maximal rate of force development (MRFD). Twenty-three women and 36 men (mean age: 24.11±2.88) were parallelized into three groups based on their CMJ height: deep front squats (FSQ, n=20), deep back squats (BSQ, n=20) and quarter back squats (BSQ¼, n=19). In addition a control group (C, n=16) existed (mean age: 24.38±0.50). Experimental groups trained 2 d·wk for 10 weeks following a strength-power periodization, which produced significant (p≤0.05) gains of the specific squat 1-RM. FSQ and BSQ attained significant (p≤0.05) elevations in SJ and CMJ without any interaction effects between both groups (p≥0.05). BSQ¼ and C did not reveal any significant changes of SJ and CMJ. FSQ and BSQ had significantly higher SJ scores over C (p≤0.05). BSQ did not feature any significant group difference to BSQ¼ (p=0.116) in SJ, whereas FSQ showed a trend towards higher SJ heights over BSQ¼ (p=0.052). FSQ and BSQ presented significantly (p≤0.05) higher CMJ heights over BSQ¼ and C. Post-test in MVC and MRFD demonstrated no significant changes for BSQ. Significant declines in MRFD for FSQ in the right leg (p≤0.05) without any interaction effects for MVC and MRFD between both FSQ and BSQ were found. Training of BSQ¼ resulted in significantly (p≤0.05) lower RFD and MVC values in contrast to FSQ and BSQ. Quarter squat training elicited significant (p≤0.05) transfer losses into the isometric maximal and explosive strength behavior. Our findings therefor contest the concept of superior angle specific transfer effects. Deep front and back squats guarantee performance-enhancing transfer effects of dynamic maximal strength to dynamic speed-strength capacity of hip and knee extensors compared to quarter squats.
tl;dr - Form > weight. Squatting deep increases explosiveness and vertical jump ability. Get low with full range of motion for best results.