Does Range of Motion in the Leg Press Matter for Quad Growth?

Range of motion (ROM)—how far a joint moves during an exercise—is a hot topic. Some argue that greater range of motion stimulates more muscle growth, and several past studies, particularly in exercises like the squat and leg press, suggest that a long ROM leads to greater hypertrophy (muscle growth) in certain parts of the quadriceps.¹ ² ³

And, if you have been on fitness social media over the last year or so, you know that stretch-mediated hypertrophy is the big thing, with gurus and influencers, sometimes with millions of followers, hyping a full (or even extreme) ROM as the greatest thing since cheese, all while claiming that they are evidence-based.

However, these studies often involve untrained individuals. And, if you look at pro bodybuilders, they often perform their reps with a limited ROM.

Enter Larsen et al.’s 2025 study, a well-controlled exploration into whether knee flexion ROM affects quadriceps hypertrophy during leg press training in resistance-trained athletes.⁴

The Study: Leg Press, Range of Motion, and Muscle Growth

This new study recruited 23 resistance-trained individuals (15 men and eight women) between 21 and 41 years, averaging 7 years of training experience.

Each participant performed unilateral (one-leg-at-a-time) leg presses for eight weeks, with one leg following a fixed ~100° knee flexion ROM, and the other leg using the participant’s maximum ROM, averaging ~154°.

Yes, the particpants were their own control group, doing fixed ROM with one leg and full ROM with the other. That kind of study is called within-subjects design and is great for controlling for individual differences like genetics or lifestyle, which might otherwise skew the results.

Training Details

Frequency: Two weekly sessions, with at least 48 hours of rest between workouts.
Reps and Intensity: Participants did the leg presses for each leg to momentary failure in the 8–12 repetition range.
Progression: Weights were adjusted weekly. If a participant could perform more than 12 reps, the researchers increased the load by 2.5–5 kg; if they couldn’t reach 8 reps, they reduced the load by the same amount.
Volume:
- Week 1: Three sets per session (6 sets per week per leg).
- Weeks 2–8: Four sets per session (8 sets per week per leg).
Cadence: They performed the concentric actions (pushing) as quickly as possible, while the eccentric actions (lowering) took ∼2 seconds.
Equipment: The study used a Rogue 45° leg press machine, with precise ROM monitoring via an electric goniometer.

They rotated which leg was trained first each week to eliminate bias from fatigue. Rest intervals were ~30 seconds between legs and over 90 seconds between sets for the same leg.

Qualified researchers supervised all sessions to make sure the participants adhered to the training protocol. They were also advised to eat a protein-rich diet (≥1.6 g/kg body mass—the amount that maximizes muscle growth potential, according to several studies) and slightly increase their caloric intake. No other lower-body training was allowed during the intervention.

Assessments

Muscle thickness of the quadriceps femoris was measured using ultrasound before and after the intervention.

Range of motion in the leg press: quadriceps femoris. — Quadriceps Femoris

Measurements were taken at the proximal (the area closest to your hip), middle, and distal (down by your knee) regions of the quadriceps to examine growth across the entire muscle.

Key Findings: ROM Differences? Not So Much

Surprise! Or maybe not. Both ROM strategies led to similar muscle growth.

Quadriceps hypertrophy ranged from 2.2% to 7.3%, regardless of whether the leg pressed deep or stopped short, with no statistically significant differences between the two conditions.
Bayesian analyses (a way of figuring out how likely something is by starting with an educated guess based on what you already know and then updating that guess as you get more evidence or information) provided moderate to extreme evidence supporting a null hypothesis—essentially, no meaningful difference between the two ROMs.
The total training volume was higher in the 100° ROM condition because you can use more weight when you don’t go deep. There might be a mechanism where lifting heavier loads with a shorter ROM might compensate for the reduced stretch in the muscle.

In short, whether participants went deep or stopped at ~100°, their muscles grew equally well.

What This Means for You

For experienced lifters, the take-home message is that a 100° knee flexion range of motion is just as effective as going all the way down in the leg press—great news if you don’t have the ankle mobility to go ATG (a$$ to grass) or prefer using the heaviest weights possible.

If a max ROM feels unstable or uncomfortable, rest easy, knowing you’re likely not leaving gains on the table.

That said, deeper ROM still has its perks:

You don’t have to go as heavy, and other muscles can piggy-back on the added ROM for more gains (like the adductors and the glutes, which grow more from deep squats than half squats), so you might not have to do as many exercises total.

Muscle growth from deep squat vs half squats — Eur J Appl Physiol. 2019 Sep;119(9):1933-1942. Effects of squat training with different depths on lower limb muscle volumes.

If your goal is strength, you want to do most of your training in the full range of motion you want to get stronger in.

Study Limitations

No study is without limitations, and this one was no different.

The study only included experienced lifters. They might not see major differences because they’re already past the point of stretch-mediated gains. Beginners, however, might benefit more from using more extended ROMs.
Eight weeks is enough to detect short-term hypertrophic changes, but longer studies might reveal differences over time.
While participants were advised to eat slightly more and maintain a protein intake of 1.6 g/kg of body weight, the researchers didn’t control or strictly track their diet.
The participants lifted their heels off the when leg pressing with the full ROM leg, which might have introduced extra instability, potentially limiting force output and diminishing the benefits of a more extended and stable ROM.

Practical Applications

A full ROM isn’t a magic ticket to big legs. If you love doing deep leg presses (or squats for that matter), keep at it. There are no downsides if you have the mobility and some benefits. But this study suggests you don’t need it to grow your quads.

If you have ankle mobility or joint limitations but can go heavier as long as you don’t go as deep, stick with a ROM that feels good with proper form. You’ll likely get great gains without putting stress on your joints.

And why not try both approaches to see what feels best and fits your long-term goals?

Final Rep

This study suggests that the choice between a full or moderate range of motion in the leg press boils down to personal preference, equipment setup, and your individual biomechanics. The gains are nearly identical whether you stop at 100° or go full depth. At least for the quads, although the glutes might have something to say about that.

The best ROM is the one you can perform consistently and safely.

So, the next time you hit the leg press, don’t sweat whether your knees hit your chest. How deep you go isn’t all that matters; it’s more about how much effort you give.

Last reviewed: 2025-12-18