When you squat or move your legs widely, your butt and inner thighs grow more than if you only do the last bit of the movement.
Scientific Claim
Full range of motion is associated with greater hypertrophy in the gluteus maximus and adductors compared to partial range of motion performed in the final part of the movement, with between-group effect sizes of 0.24–0.25.
Original Statement
“fROM elicited greater muscle growth on the gluteus maximus and adductors than pROM in the final part of the ROM (between-groups ES: 0.24–0.25).”
Evidence Quality Assessment
Claim Status
overstated
Study Design Support
Design cannot support claim
Appropriate Language Strength
association
Can only show association/correlation
Assessment Explanation
The abstract implies causation ('elicited greater'), but the underlying studies' designs are unknown. Only an associative interpretation is valid.
Gold Standard Evidence Needed
According to GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this specific claim, ordered from strongest to weakest evidence.
Systematic Review & Meta-AnalysisLevel 1aIn EvidenceWhether full ROM consistently leads to greater gluteal and adductor growth across populations and exercise types.
Whether full ROM consistently leads to greater gluteal and adductor growth across populations and exercise types.
What This Would Prove
Whether full ROM consistently leads to greater gluteal and adductor growth across populations and exercise types.
Ideal Study Design
A systematic review and meta-analysis of 15+ RCTs comparing full ROM vs. final partial ROM in hip-dominant exercises (e.g., squats, hip thrusts, leg adduction machines) in healthy adults, measuring muscle thickness via ultrasound or MRI at 8–16 weeks, with standardized volume and intensity.
Limitation: Cannot determine if benefits are due to stretch tension or total mechanical load.
Randomized Controlled TrialLevel 1bCausal effect of ROM on gluteus maximus and adductor hypertrophy.
Causal effect of ROM on gluteus maximus and adductor hypertrophy.
What This Would Prove
Causal effect of ROM on gluteus maximus and adductor hypertrophy.
Ideal Study Design
A double-blind RCT of 40 adults performing 12 weeks of hip thrusts or squats with matched volume, randomized to full ROM or final partial ROM (0–45°), with muscle cross-sectional area measured via MRI at baseline and endpoint.
Limitation: Limited generalizability to untrained or older populations.
Prospective Cohort StudyLevel 2bLong-term association between ROM use and gluteal development in real-world training.
Long-term association between ROM use and gluteal development in real-world training.
What This Would Prove
Long-term association between ROM use and gluteal development in real-world training.
Ideal Study Design
A 2-year cohort study of 150 resistance-trained individuals tracking their squat depth and adductor exercise ROM, with DEXA scans of hip musculature at 6, 12, and 24 months, adjusting for training frequency and nutrition.
Limitation: Cannot control for self-selection bias in ROM preference.
Evidence from Studies
Supporting (1)
Which ROMs Lead to Rome? A Systematic Review of the Effects of Range of Motion on Muscle Hypertrophy
The study found that doing full squats or similar movements (full range of motion) builds more glute and inner thigh muscle than stopping short at the bottom of the movement, and the numbers back up the claim exactly.