Effects of squat training with different ranges of motion on muscle strength, jump performance, and change of direction ability

BACKGROUND: This study aimed to examine the effects of short-term, high-load full squat (F-SQ) and half squat (H-SQ) training on muscle strength, jump performance, and change of direction in resistance-trained athletes. METHODS: Thirty resistance-trained males (aged 19.4±0.8 years; height 170.6±6.0 cm; body mass 70.4±6.4 kg) were allocated to three groups: F-SQ, H-SQ, and control. The F-SQ and H-SQ groups performed squat training twice weekly for 3 weeks, with intensity progressively increasing from 85% to 90% of one-repetition maximum (1RM). Post-intervention, participants underwent 1RM, pro-agility, and vertical jump tests. RESULTS: The H-SQ group exhibited significantly higher training volume (P=0.001), while the F-SQ group achieved greater concentric work volume (P=0.005) and lifting velocity (P=0.017-0.048). A significant interaction was observed for F-SQ 1RM (P=0.025), with both the F-SQ (P=0.032) and H-SQ (P=0.024) groups showing significant improvements. No significant interaction was found in the pro-agility test (P=0.225), although a significant main effect of time was noted (P=0.001). The H-SQ group demonstrated slightly larger effect sizes (ES=0.50[95%CI: -0.94, 0.91]). CONCLUSIONS: Although training volume and quality differed between protocols, both F-SQ and H-SQ training yielded comparable improvements in muscle strength and performance, with no significant between-group differences.