REF-1085 · Sánchez-Valdepeñas et al., 2026 · Journal of Strength and Conditioning Research, · Paper · PubMed
Four velocity-loss thresholds in the full squat at 55-70% 1RM (0, 10, 20 and 40%): 20% gave the largest 1RM and heavy-load velocity gains; 40% showed the largest muscle-size effect size but no significant group difference, and the smallest strength gains
The authors compared four velocity-loss (VL) thresholds — the drop in bar speed within a set at which the set is stopped — during a full-squat programme with loads of 55-70% 1RM, measuring muscle size, strength, jump and fatigue. Content from the abstract only.
Participants
Fifty-one moderately resistance-trained men, randomly assigned to VL0, VL10, VL20 or VL40. Age and group sizes are not given in the abstract.
Protocol
Full squat, loads 55-70% 1RM, 16 sessions (2 per week); groups differed only in the VL threshold reached within the set.
Pre/post: vastus lateralis cross-sectional area (CSA), countermovement jump, maximal isometric squat, incremental loading squat test, fatigue squat test.
Key Results
All groups increased muscle CSA (p < 0.01); group × time interaction p = 0.18; effect sizes VL0 0.19, VL10 0.22, VL20 0.19, VL40 0.47.
Significant group × time interactions for 1RM (p = 0.03) and velocity against heavy loads (p = 0.02), with VL20 obtaining the greatest gains.
Strength effect sizes: VL0 0.50-1.70; VL10 0.53-2.34; VL20 0.81-2.72; VL40 0.52-0.86.
Authors' conclusion: moderate VL thresholds elicit the greatest strength gains; higher VL thresholds were associated with greater CSA increases (no significant interaction) and comparatively lower strength improvements.
Practical Application
"How close to failure should my squat sets go if I want strength?" In 51 trained men over 8 weeks of squats at 55-70% 1RM (four-arm RCT), stopping each set at about 20% velocity loss gave the largest 1RM gains; going to 40% (the closest to failure of the four) gave the smallest strength gains, and its larger muscle-size effect was not statistically different from the other groups.
Not from this paper; the base's own practice (SYNTH-43): without a velocity device, "stop the set when a rep clearly slows" is the field version of a moderate velocity-loss cap.
Inference, not tested here: for a cyclist whose lifting serves the bike, the lower fatigue cost of a 20% cap is the point — strength without the soreness that eats into key rides.
Limitations
Four arms on 51 men: about 13 per group, so the non-significant hypertrophy interaction may be a power problem; the abstract gives no group sizes, dropouts or confidence intervals.
Muscle size measured as vastus lateralis CSA (the abstract does not say at how many sites).
Moderately trained men, squat only, 8 weeks; women, other lifts, heavier loads and endurance athletes not studied.
How this entry was checked and changed
Why this level
51 randomised (rubric: parallel RCT ≥40 = A-), held at B+ because four arms leave roughly 13 per group and the hypertrophy interaction was not significant