For most lifters and most goals, full-range reps are the default — a 2013 study in the Journal of Strength and Conditioning Research by Bloomquist and colleagues found deep squats produced more thigh muscle growth than shallow ones — but the gap is narrower than gym legend claims. A 2022 trial in the European Journal of Sport Science by Martins-Costa and colleagues found lengthened partial reps built similar quadriceps growth to full range in untrained lifters. Use full range as the base; use partials deliberately, not as a shortcut.
This site publishes information, not medical advice. If pain, injury, or a medical condition affects your training, have a clinician or qualified professional clear your exercise selection first.
What counts as a partial rep?
Any repetition that skips part of the joint's range — quarter squats, half biceps curls, or deliberately partial work at the stretched end of a movement. Worth defining terms: the "lengthened" position is where the muscle is longest — the bottom of a curl, the deep position of a squat — and that end has drawn most of the recent research attention.
Partials are not a cheat by definition. Loaded progressively and chosen for a reason, they are a legitimate tool. Done to make the set easier or feed the ego, they are just a lighter set with worse mechanics.
What does the evidence favor for muscle growth?
The contested picture, presented honestly. On one side: Bloomquist's 2013 JSCR squat trial favored deep range for quad growth, and the broader comparison literature generally rewards training at long muscle lengths — the same direction seen in the 2021 hamstring work by Maeo and colleagues in Medicine and Science in Sports and Exercise, where long-length training outgrew short-length. On the other side: the 2022 Martins-Costa trial found lengthened partials roughly matched full range for quad hypertrophy over eight weeks in untrained men, and similar findings have followed.
The honest synthesis: stretched-position work seems to carry most of the growth signal, full range gets you that plus general range and skill, and shortened partials — the easy top half of a movement — have the weakest showing.
What about strength?
Strength is joint-angle specific, and the evidence reflects it: Bloomquist's deep-squat group improved max squat more, while the shallow group gained more in their trained half range. If your goal is a bigger total or a sport-specific position, train the range you want to be strong in — with full range as the foundation for general capacity, per standard NSCA programming guidance.
| Approach | Best evidence for | Common use in cited sources |
|---|---|---|
| Full range | General hypertrophy, strength transfer, mobility under load | Default for most exercises |
| Lengthened partials | Hypertrophy roughly matching full range (Martins-Costa et al., 2022) | Finishers or substitutes when full range is limited |
| Shortened partials | Overload in specific top-end positions | Targeted use, weakest general evidence |
Related stories: How Deep Should You Squat? Mobility Limits vs. Your Anatomy · Shoulder Mobility for Overhead Work: Build the Full Arc.
Do full-range reps improve mobility too?
Plausibly yes — and it is the most underrated argument for depth. Training through a long range loads the muscle in its stretched position, which trains active range rather than passive tolerance. This is one reason strength coaches treat loaded full-range work as mobility training with a barbell. Direct long-term trials are still limited, so treat it as well-reasoned practice, not proven law.
How should you actually program this?
- Make controlled full-range reps the base of most exercises — a pace you could stop mid-rep, no bouncing.
- Add lengthened partials sparingly: a partial-only set after full-range sets, or as a substitute when an injury or equipment limit restricts range.
- Save shortened partials for specific top-end goals, like rack pulls for a sticking point, and treat them as specialization.
- Progress load within the range you can control — depth you cannot own under load is not depth.
When to see a professional
See a physical therapist or qualified coach if deep positions consistently produce joint pain, if an old injury caps your range asymmetrically, or if you are returning to training after surgery. Reduced range after an injury often needs progressive reloading rather than avoidance — and a professional can tell you which.
FAQ
Are half squats a waste of time?
Not a waste — a specialization. The 2013 Bloomquist trial found the shallow-squat group gained in their trained range while the deep group gained more overall. If you have a specific half-range goal, half squats are defensible; for general development, deep controlled squats win the comparisons.
Do lengthened partials count if I can't do full range?
Yes — the 2022 Martins-Costa trial found lengthened partials produced similar quadriceps growth to full range over eight weeks in untrained lifters. If injury, equipment, or mobility limits full range, work the stretched position under control. Just keep testing whether full range returns as capacity builds.
Is full range always safer than partials?
No — safety depends on load and control, not range alone. Deep reps with manageable load are well tolerated in healthy lifters, while partial reps with ego-weight through a short arc strain joints and tendons more, not less. Match the load to the range you can control and stop where form breaks.
Does tempo matter as much as range?
They trade off. A controlled tempo lets you own deeper positions with less weight; rushing turns deep reps into bouncing partials. Commonly used coaching guidance favors a pace you can stop at any point. Range without control is not the range the research measured.