Effects of regular and slow speed resistance training on muscle strength.
Level 3 - non-randomized controlled study
Controlled comparative intervention study without explicit reporting of randomization
What was done
Across two studies, 147 untrained men (n=65) and women (n=82) with a mean age of 53.6 years performed resistance training 2 to 3 times per week for 8 to 10 weeks on a 13-exercise Nautilus circuit (one set per exercise). Participants completed either regular-speed repetitions (8–12 reps/set, 7 s each: 2 s lifting, 1 s pause, 4 s lowering) or a Super Slow protocol (4–6 reps/set, 14 s each: 10 s lifting, 4 s lowering). Strength outcomes were tested using 10-repetition maximum (10-RM) for the regular-speed group and 5-repetition maximum (5-RM) for the slow-speed group.
What was found
In both studies, Super-Slow training resulted in approximately 50% greater strength increases (p < 0.001) for both men and women compared to regular-speed training. - Study 1: Super-Slow group increased strength by a mean of 12.0 kg vs. 8.0 kg in the regular-speed group (p < 0.001). - Study 2: Super-Slow group increased strength by a mean of 10.9 kg vs. 7.1 kg in the regular-speed group (p < 0.001).
Why it matters
The results suggest that slowing lifting speed during single-set machine resistance training can elicit substantially greater strength adaptations in middle-aged adults without requiring additional training volume.
Limits
The primary strength outcomes were tested using different metrics (10-RM vs. 5-RM) between groups, introducing substantial testing specificity bias. The abstract does not mention randomization, blinding, dropouts, or long-term retention, and findings are limited to untrained middle-aged adults using machine circuits.
Cited by
- supports Super-slow strength training with high time-under-tension (up to about 2 minutes) produces significant strength and cardiovascular adaptations with low training volume and lower injury risk.