Effect of velocity loss during squat training on neuromuscular performance

Abstract

This study aimed to compare the effects of three resistance training (RT) programs differing in the magnitude of velocity loss (VL) allowed in each exercise set: 10%, 30%, or 45% on changes in strength, vertical jump, sprint performance, and EMG variables. Thirty‐three young men were randomly assigned into three experimental groups (VL10%, VL30%, and VL45%; n = 11 each) that performed a velocity‐based RT program for 8 weeks using only the full squat exercise (SQ). Training load (55–70% 1RM), frequency (2 sessions/week), number of sets (3), and inter‐set recovery (4 min) were identical for all groups. Running sprint (20 m), countermovement jump (CMJ), 1RM, muscle endurance, and EMG during SQ were assessed pre‐ and post‐training. All groups showed significant (VL10%: 6.4–58.6%; VL30%: 4.5–66.2%; VL45%: 1.8–52.1%; p < 0.05–0.001) improvements in muscle strength and muscle endurance. However, a significant group × time interaction (p < 0.05) was observed in CMJ, with VL10% showing greater increments (11.9%) than VL30% and VL45%. In addition, VL10% resulted in greater percent change in sprint performance than the other two groups (VL10%: −2.4%; VL30%: −1.8%; and VL45%: −0.5%). No significant changes in EMG variables were observed for any group. RT with loads of 55–70% 1RM characterized by a low‐velocity loss (VL10%) provides a very effective and efficient training stimulus since it yields similar strength gains and greater improvements in sports‐related neuromuscular performance (jump and sprint) compared to training with higher velocity losses (VL30%, VL45%). These findings indicate that the magnitude of VL reached in each exercise set considerably influences the observed training adaptations.

The effects of different intra-set velocity loss thresholds on lower-limb adaptations to resistance training in young adults: A systematic review and meta-analysis

“…After screening the title, abstract, and full-text (using Rayyan-web App, http://rayyan.qcri.org), 10 studies met our eligibility criteria. One study [45] was later included by tracking newly published articles. Thereby, a total of 11 studies were included in this systematic review (Table 1).…”

“…and seven [22,23,28,29,32,45,46] included high percentages of VL (≥ 30%). The total number of repetitions during the RT program ranged from ~48 [23] to ~501 [45]. The average number of total repetitions performed during the RT program across studies according to the intra-set VL magnitude…”

“…The intra-set VL magnitude varied from 0% to 45%. Five studies [23,24,29,31,45] included low magnitudes of intraset VL (< 15%), eight [16,[22][23][24]28,32,46,47] included moderate VL magnitudes (≥ 15% and < 30%),…”

“…One study [46] was rated as having a high risk of effort bias since it did not report whether the participants were encouraged to exert maximum effort in lifting. Four studies [24,29,45,46] were classified to be at high risk of familiarization bias due to the lack of familiarization sessions and insufficient details about the participants' experience with the procedures of the study.…”

“…The effects of intra-set VL on running sprint time were investigated in eight studies (pooled n = 277 participants). Three studies included 20 m sprint times [16,22,24], one study included 30 m sprint times [28], and four studies measured sprint times for both 10 m and 20 m [23,29,45,46]. The results of the overall effects between pre-and post-intervention showed a significant, small improvement in sprint time (p = 0.001; SMD = -0.28, 95% CI: -0.45 to -0.11).…”