The effects of lengthened-partial range of motion resistance training of the limbs on arm and thigh muscle area: A multi-site randomised trial.
Level 2 - randomized trial
Multi-site randomized controlled cluster trial
PubMed 41055237 · doi:10.1080/02640414.2025.2567805
What was done
A pre-registered randomized controlled cluster trial across 15 sites compared 12 weeks of lengthened-partial range of motion (lpROM, n = 163) against full range of motion (fROM, n = 134) resistance training. Outcomes evaluated were estimated muscle cross-sectional area (CSA) of the upper arm and thigh, and strength on chest press, leg press, and pulldown. Equivalence was tested against a smallest effect size of interest (SESOI) of [-0.1, 0.1] with an adjusted alpha of 0.005.
What was found
The condition-by-time interaction estimate was -0.032 for arm estimated muscle CSA (equivalence p = 0.071) and 0 for thigh estimated muscle CSA (equivalence p = 0.019). Because the adjusted alpha was 0.005, the study could not statistically reject the null hypothesis of non-equivalence under its formal criteria, but observed between-condition differences were small and practically equivalent. Strength values and statistics were not reported in the abstract.
Why it matters
This large multi-center trial demonstrates that lengthened-partial range of motion and full range of motion resistance training yield comparable limb muscle hypertrophy over 12 weeks.
Limits
Participant demographics (age, sex, training status) and exact exercise selection or loading protocols are not described in the abstract. Numerical results and statistical findings for strength outcomes were omitted. The specific measurement modality used to estimate muscle cross-sectional area was not stated.
Cited by
- supports Partial repetitions performed specifically in the lengthened position produce similar muscle hypertrophy to full range of motion exercises.