Does Pilates Build Muscle? What the Research Actually Shows

Yes, Pilates builds muscle — but it builds it the way a spring builds it, not the way a barbell does, and the difference matters more the stronger you already are. If you are new to resistance work, or coming back after a long gap, you will almost certainly add real strength and a little muscle in your first few months of consistent Pilates. If you have been squatting heavy for five years, Pilates will make you better at controlling what you have without adding much on top of it. Most of the confusion around this question comes from people arguing about two different starting points.

What the Research Actually Shows

The honest summary is that Pilates produces measurable strength gains, and in head-to-head trials it holds its own against other forms of exercise — but the evidence base is thinner than either its fans or its critics admit.

A 2022 systematic review published in Heliyon pooled eleven randomised controlled trials covering 689 participants, comparing Pilates against strength training, stretching, yoga, water aerobics, balance work and physiotherapy. Interventions ran about twelve weeks at roughly three sessions a week. The reviewers found no statistically significant difference between Pilates and the comparison exercises on any of their primary strength outcomes — dynamic, isometric or endurance. Pilates on its own produced strength improvements of roughly 27% from before to after the interventions. The authors were careful to rate their own certainty as very low to low, because the included studies were methodologically modest and the samples were small.

On body composition specifically, a 2025 randomised controlled trial in Scientific Reports put 47 overweight and obese women aged 30 to 60 through eight weeks of reformer Pilates, three times a week, 50 to 60 minutes a session, with spring resistance progressing from beginner to advanced across the block. Compared to controls, the exercise group significantly improved grip strength, reduced body fat percentage, and increased muscle mass. Eight weeks. That is not nothing.

So: strength, yes, reliably. Muscle mass, yes, in populations with room to gain. Whether it beats a well-run resistance program for pure size — no study I have read supports that claim.

Why Springs and Bodyweight Count as Resistance

A lot of people assume Pilates cannot build muscle because the loads look light. That assumption rests on an old idea — the classic repetition continuum, where heavy loads build strength, moderate loads build size, and light loads only build endurance. That model has aged badly.

A re-examination of the repetition continuum published in Sports concluded that similar whole-muscle growth can be achieved across a wide spectrum of loads, anywhere from about 30% of your one-rep maximum upwards, provided the sets are taken to or near muscular failure. Below roughly 30% of maximum, growth is compromised. And the studies that found poor results from light loads generally had people stopping well short of real fatigue.

That is the whole story in one paragraph. Effort is the variable, not the equipment. Two red springs on a reformer footwork series, taken until your legs are genuinely shaking, sits comfortably inside the range where hypertrophy happens. Thirty half-hearted repetitions of the same thing does not.

Muscle does not know whether the tension came from a spring, a band, or a dumbbell. It knows how hard the fibres worked and whether you asked more of them this month than last.

Marisol Quintero

Where Pilates Falls Short for Muscle Growth

Here is the part studios do not put on the website. Pilates has two structural disadvantages for building size, and neither is fixable by trying harder in class.

The first is progression. Springs come in fixed increments, and on most apparatus you run out of them. A dumbbell rack goes from 2 kg to 50 kg in small steps; a reformer gives you maybe four meaningful settings for a leg press, and once you can do thirty controlled repetitions on the heaviest one, the machine has nothing left to offer your quadriceps. Progressive overload is the engine of muscle growth, and Pilates apparatus runs out of road.

The second is coverage. Pilates loads the trunk, hips, shoulder girdle and posterior chain beautifully. It does very little heavy horizontal pressing or vertical pulling, and the calves and hamstrings get comparatively light attention. The 2026 ACSM resistance training guidelines recommend training all major muscle groups at least twice weekly, with roughly ten sets per muscle group per week for growth and loads near 80% of maximum for peak strength. A typical mat or reformer class is not built to deliver that per-muscle volume, and it does not need to be — that is not what it was designed for.

Goal	Pilates alone	Loaded resistance training
Trunk and hip strength	Excellent	Good
Muscular endurance	Excellent	Moderate
Visible size gain	Modest, mostly in beginners	Strong
Maximal strength	Limited	Strong
Movement control and range	Excellent	Variable

Worth noting on that last row of the strength column: the Sports paper found that heavy loading's advantage for maximal strength shrinks when strength is tested on neutral equipment rather than the exact lift trained, which suggests a good chunk of it is specificity rather than a fundamentally different adaptation.

Who Gains the Most, and Who Plateaus

Your training history decides almost everything about the answer you will get.

• Untrained or long-detrained: the biggest and fastest responders. Nearly any progressive resistance stimulus produces strength and some size, and Pilates supplies that comfortably.
• Cardio-dominant athletes: runners, cyclists, swimmers who have never loaded their hips or trunk usually gain quickly, and it shows up as better mechanics as much as bigger muscle.
• Older adults: the Heliyon review's average participant was around 60, and it still found meaningful gains — this is a population where preserving muscle is the whole point. If you are over 60 or managing any joint or cardiac condition, talk to your clinician before you start pushing spring loads.
• Experienced lifters: the plateau group. Expect better control, mobility and trunk stiffness, not new muscle.

How to Make Your Pilates Build More

If muscle is genuinely your goal and you want Pilates to carry as much of that load as it can, this is where I would put the effort.

Go heavier and shorter. Ask your instructor for a heavier spring and fewer repetitions rather than the endurance sets most classes default to. Take the last few repetitions of a loaded series close to real fatigue — not to collapse, but far enough that the final two are genuinely hard. Favour single-leg and single-arm work, which doubles the load per limb without touching the springs. Slow the eccentric; a four-second lower on footwork changes the exercise entirely. And train the same tissue at least twice a week, which usually means two or three sessions rather than one.

Then be realistic about the ceiling. If you want visible size, add two short loaded sessions a week — squats, hinges, presses, rows — and keep Pilates for what it does better than anything else. That combination beats either one alone, and it is what I program for almost every athlete I work with.

The Honest Verdict

Pilates builds real, measurable strength, and it builds some muscle in people who have room to gain it. The trials support that. What it does not do is compete with a barbell for maximum size or maximum strength, because it cannot progress load finely enough or cover every major muscle group at sufficient volume.

Treat that as a description, not a criticism. Pilates was never designed as a hypertrophy protocol. It was designed to make a body move well under control, and it happens to be strong enough as a resistance stimulus that beginners get muscle as a bonus. If you are starting from little or nothing, start here — three sessions a week, heavier springs than feel comfortable, and give it twelve weeks before you judge it. If you are already strong and you want to be bigger, keep the Pilates and add the weights.

Frequently asked

How long does it take to see muscle gains from Pilates?

Most people notice strength changes within four to six weeks and visible changes closer to twelve. An eight-week reformer trial in overweight and obese women recorded measurable increases in muscle mass and grip strength at three sessions a week.

Is Pilates enough on its own for strength training?

For general health and for someone new to resistance work, yes, it can be. If your goal is maximal strength or visible size, current guidelines point to heavier loading across all major muscle groups, which a typical Pilates class does not deliver.

Does reformer Pilates build more muscle than mat Pilates?

Generally yes, because springs let you load a movement well beyond bodyweight and adjust the resistance. Mat work is limited to your own body weight and leverage, which caps how much you can progress once you are reasonably strong.

Will Pilates make me bulky?

No. Building substantial muscle size requires high per-muscle training volume with progressively heavier loads, which Pilates apparatus is not designed to provide. Expect a stronger, more controlled body rather than a noticeably larger one.