Is Reformer Pilates a Good Workout? (Does It Build Muscle?)
- 2 days ago
- 5 min read
TL;DR: Reformer pilates is a genuinely good workout, but a specific kind. It is resistance-based strength training that builds core strength, muscular endurance and lean, balanced muscle, with very low joint impact. It is not heavy hypertrophy training, so it will not build bulk the way weights do, and it is not cardio unless you take a faster, cardio-style class. It is an excellent main workout for functional strength and a strong complement to lifting or running.
Ask someone who lifts heavy whether reformer pilates is a good workout and you will often get a smirk. Then they take a class, shake through the first ten minutes, and walk out reconsidering. We have run reformer classes at our Bondi studio for over 15 years, with everyone from nervous beginners to former rugby players on the machines, and the "it's just stretching" idea rarely survives a single session. So is reformer pilates a good workout? Yes, but it is a specific kind of good, and knowing which kind tells you whether it fits your goals.
Is reformer pilates a good workout?
Yes. Reformer pilates is resistance training that works your whole body against the adjustable spring load, building strength, muscular endurance and control with almost no impact on your joints. The spring system creates tension through the entire range of a movement, not just at the top, so muscles work harder than they look like they are working from the outside. Where it sits apart from the gym is the kind of result it produces: lean, balanced, functional strength rather than size. For most people, that is exactly the workout they actually want.
Does reformer pilates build muscle?
Yes, but it builds endurance and tone more than bulk. Reformer pilates uses moderate spring resistance, slow controlled tempo and long static holds, which develops muscular endurance and lean, defined muscle rather than the size you get from heavy, low-rep lifting. A 2025 randomised controlled trial published in Scientific Reports found that two to three reformer sessions a week improved muscle strength, endurance and body composition over eight weeks. You will get stronger and more defined, especially through the core, glutes and legs. You will not get visibly bulkier, which for most people is the point rather than a drawback.
Is reformer pilates strength training?
Yes. Strength training simply means working muscles against resistance, and that is exactly what the reformer's springs provide. The difference from a weights room is in the loading. Reformer uses lighter, continuous resistance with more repetitions and more stability demand, so it trains your muscles to be strong, controlled and resilient through full ranges of motion. It is genuine strength work, just biased toward endurance and control rather than maximum force. The springs even allow progressive overload, the core principle behind getting stronger, by increasing resistance or difficulty as you advance.
Is reformer pilates cardio?
Mostly no, and that is worth being honest about. A standard reformer class keeps a slow, controlled tempo that does not lift your heart rate into a true aerobic zone for long enough to count as cardio. Writing in The Conversation, exercise scientists note that pilates delivers broad health benefits but that most classes are not aerobic exercise. The exception is faster, circuit-style formats. Our Cardio Fusion Reformer class at Bondi deliberately speeds the work up to push your heart rate, but a typical Essentials or Flow class is strength and control, not cardio. If aerobic fitness is your goal, pair reformer with walking, running or swimming.
How reformer pilates compares to other workouts
No single workout does everything, so the honest way to judge reformer is against what you want from it.
Goal | Reformer pilates | Heavy weights | Running / HIIT | Yoga |
Maximum muscle size | Limited | Best | No | No |
Functional and core strength | Excellent | Good | Limited | Moderate |
Muscular endurance and tone | Excellent | Moderate | Moderate | Moderate |
Cardio fitness | Low | Low | Best | Low |
Mobility and posture | Excellent | Limited | Limited | Excellent |
Joint impact | Very low | Moderate | High | Very low |
Read across your own priorities. If you want size and raw strength, weights win. If you want aerobic fitness, running wins. If you want a strong, mobile, resilient body that holds up day to day, reformer is hard to beat, and it pairs well with all of them.
Who is reformer pilates the best workout for?
Reformer pilates is an outstanding main workout for anyone chasing functional strength, core control, posture and injury resilience, and a powerful complement for people who already lift or run. It suits beginners returning to exercise, people managing their joints, and athletes who need stability and mobility to protect their main sport. It is a weaker fit as your only workout if your single goal is maximum muscle size or competitive aerobic fitness, in which case it works best alongside heavier lifting or dedicated cardio.
How to make reformer pilates a harder workout
If a class feels too easy, the difficulty is yours to adjust, and it rarely means going faster. Add resistance by increasing the spring load on the exercises you have mastered. Slow the tempo down, because controlled, slower reps under tension are harder, not easier. Progress your classes as you build, moving from Essentials to Flow to Progressive Reformer, where the exercises demand more strength, balance and coordination. Go two to three times a week so your body actually adapts. The reformer scales a long way, most people simply have not met the top of it yet.
Frequently asked questions
Does reformer pilates build muscle or just tone you?
It builds real muscle, weighted toward endurance and definition rather than size. You develop lean, strong, defined muscle, particularly in the core, glutes and legs, but not the bulk that comes from heavy weightlifting. "Tone" is simply muscle you have strengthened without adding much size, which is what reformer does well.
Can reformer pilates replace the gym?
For functional strength, core, posture and low-impact conditioning, reformer pilates can absolutely be your main workout. If your goals include maximum muscle size or heavy strength numbers, it works best alongside weights rather than fully replacing them. Many people use reformer as their strength base and add a little cardio.
Will reformer pilates make me bulky?
No. The moderate resistance and higher repetitions build lean, defined muscle rather than size. Reformer is far more likely to make you look longer and more toned than bigger.
Is reformer pilates better than weights?
Neither is better, they do different jobs. Weights are better for maximum size and raw strength. Reformer is better for core strength, muscular endurance, mobility, posture and joint-friendly conditioning. The strongest, most resilient bodies usually use both.
How long until reformer pilates changes your body?
Most people feel stronger and more controlled within two to three weeks, and see visible changes in muscle definition from around four to eight weeks of training two to three times a week.
So, is reformer pilates the right workout for you?
If you want a strong, capable, low-impact body and you are not chasing bodybuilding size, reformer pilates is one of the most effective workouts you can do, and it complements whatever else you love. The only way to know how it feels for your body is to get on the machine.
Try it at our Bondi studio on the 21-day unlimited trial. Start in Essentials Reformer, then feel how much harder it gets as you progress. Start your 21-day unlimited trial.
