Range of motion (full vs partial reps)
Full range of motion generally builds more strength and lower-body muscle than short, partial reps. The key seems to be training the muscle in its stretched (lengthened) position: partial reps in the lengthened part of the movement can match full range, while partials in the shortened part are clearly worse.
What the science says
- Full range beats partial range overall Moderate evidence
Pallarés et al.'s 2021 meta-analysis found full ROM produced significantly greater strength gains and lower-limb hypertrophy than partial ROM.
- Training at long muscle lengths is what counts Moderate evidence
Kassiano et al.'s 2023 systematic review found that full ROM and partials in the initial (stretched) part of the movement produced greater growth in several muscles than partials in the final (shortened) part.
- Lengthened partials can match full range Limited evidence
In a within-person trial of trained lifters, Wolf et al. (2025) found lengthened partial reps gave similar upper-body growth and strength-endurance gains to full ROM. It is a single 8-week study.
- Deep squats grow more glutes and adductors Limited evidence
Kubo et al. (2019) found full squats increased gluteus maximus and adductor volume more than half squats, while quadriceps growth was similar.
How to apply it
Use the fullest range you can control, emphasize the stretched position, and use lengthened partials as an optional add-on rather than a replacement for full reps.
Who should be careful
Range of motion should be limited by control and comfort, not forced; pain in a deep position is a reason to reduce range and consult a qualified professional. People with joint conditions or after surgery should follow individual guidance from a physiotherapist or physician.
Frequently asked questions
Are full reps better than partial reps?
Generally yes. A meta-analysis found full ROM produced greater strength and lower-body muscle growth than partial ROM.
Are lengthened partials as good as full reps?
Possibly. Partials in the stretched part of the movement can match full range in some studies, while partials in the shortened part are clearly worse, but the evidence is still small.
How deep should I squat?
At least to parallel, and deeper if you can control it. Full squats grew the glutes and adductors more than half squats in one trial, with similar quadriceps growth.
Scientific references
- Effects of range of motion on resistance training adaptations: A systematic review and meta-analysis
- Which ROMs Lead to Rome? A Systematic Review of the Effects of Range of Motion on Muscle Hypertrophy
- Lengthened partial repetitions elicit similar muscular adaptations as full range of motion repetitions during resistance training in trained individuals
- Effects of squat training with different depths on lower limb muscle volumes
More training variables
- Training volume (sets per muscle per week) Strong evidence
Weekly volume, counted as hard sets per muscle, is one of the best-supported drivers of muscle growth: more sets bring more growth, with diminishing returns.
- Training frequency (sessions per muscle per week) Moderate evidence
When weekly volume is the same, how many days you split it across makes little difference to muscle growth.
- Rest intervals between sets Moderate evidence
Very short rests (under about a minute) tend to cost you reps and slightly blunt growth; past about 90 seconds, extra rest brings little added hypertrophy.
- Load and rep range (heavy vs light) Strong evidence
Muscle grows similarly across a wide range of loads, from heavy sets of 5 to light sets of 30, as long as sets are taken close to failure.
- Proximity to failure (reps in reserve) Moderate evidence
Sets need to be hard to drive growth, and hypertrophy tends to rise the closer you get to failure.
- Repetition tempo (time under tension) Limited evidence
Deliberately slowing your reps to maximize 'time under tension' does not build more muscle.