What Is Pilates? A Complete Guide to the Method, Its Principles and Who It's For
By Katherine, Lead Instructor, Certified Pilates Instructor · Last updated: September 2026
Pilates is a mind-body exercise method built on controlled, precise movement, breath and core control, performed either on a mat using body weight or on spring-loaded equipment such as the reformer. It was developed by Joseph Pilates in the early twentieth century, who called it "Contrology" to emphasize conscious control of movement. The method prioritizes quality of movement over number of repetitions.
Key takeaways
Pilates ("Contrology") was developed by Joseph Pilates, a German-born trainer who refined his system during and after the First World War and later taught it in New York City.
It uses springs (on equipment like the reformer) or your own body weight (on a mat) as resistance, with an emphasis on control and precision rather than doing more repetitions.
The commonly cited "six principles" — concentration, control, centring, breath, precision and flow — were distilled by later teachers to summarize his ideas, not written by Joseph Pilates himself as a numbered list.
"Classical" Pilates aims to teach the original repertoire faithfully; "contemporary" Pilates builds on it with current movement science and modified positions.
Pilates can suit a wide range of people when the program is adapted to them, though specific populations (beginners, pregnancy, posture concerns) have their own considerations.
Who was Joseph Pilates, and where does the name come from?
Joseph Hubertus Pilates was born on December 9, 1883, in Mönchengladbach, Germany, and died on October 9, 1967, in New York City (Joseph Pilates, Wikipedia). As a child he was often unwell, and he later worked as a gymnast, boxer and circus performer before moving to England in 1912 (Joseph Pilates, Wikipedia).
When the First World War broke out, Pilates — a German national living in England — was interned as an "enemy alien." He was first interned at Lancaster Castle, then transferred to Knockaloe, a large internment camp on the Isle of Man, for the remainder of the war (Joseph Pilates, Wikipedia). It was there, working with fellow internees, that he began developing the exercise system he called "Contrology," reportedly drawing inspiration from the movement of animals, including the camp's cats (Popular Science). Some accounts describe him rigging springs to hospital beds to help bedridden internees move against resistance — an early version of what became the reformer — though a local historical trust notes this detail is not fully documented (Popular Science).
Pilates emigrated to the United States in the mid-1920s with his partner, Clara, and the two opened a New York City studio — reportedly called the Joseph H. Pilates Universal Gymnasium — that operated for decades and attracted prominent dancers, including George Balanchine and Martha Graham (Joseph Pilates, Wikipedia; Popular Science). He published two books, Your Health (1934) and Return to Life Through Contrology (1945), and held more than 25 patents for exercise equipment over his lifetime (Joseph Pilates, Wikipedia). He continued teaching and staying visibly fit into his eighties, which — along with his equipment patents — helped cement his reputation as a serious authority on physical conditioning rather than a passing fitness trend (Popular Science).
He called his system "Contrology" throughout his life; the name "Pilates" only became the common term for the method after his death, as his students carried it forward. In 2000, a U.S. federal court ruled that "Pilates" was a generic exercise term — like "yoga" or "aerobics" — that no single company could trademark, which is part of why the name is used so widely today by studios and instructors who trained in different lineages (Pilates, Inc. v. Current Concepts, Inc., 120 F. Supp. 2d 286 (S.D.N.Y. 2000), CourtListener).
How does Pilates actually work?
Every Pilates exercise asks you to move with control against resistance, while paying close attention to alignment and breath. Where that resistance comes from depends on the format:
On a mat, resistance comes mainly from your own body weight and gravity, plus small props like a resistance ring or light hand weights in some classes.
On equipment such as the reformer, Cadillac or chair, resistance comes from springs, which can be adjusted to make an exercise easier or harder and can also assist a movement rather than resist it.
A core idea across both formats is that how you move matters more than how many repetitions you do. A Pilates set is usually short — often 6 to 10 controlled repetitions — with attention on the quality of each one: the alignment of the spine and pelvis, the timing of the breath, and which muscles are doing the work. This is different from a training style built around fatiguing a muscle through a high volume of repetitions.
Where does the idea of "six principles" come from?
Many Pilates teachers describe the method through six ideas: concentration, control, centring, breath, precision and flow. These are genuinely useful for understanding what a well-taught class is asking of you, but it is worth knowing where they came from: Joseph Pilates did not publish this list himself. His own writing, particularly Return to Life Through Contrology, discussed related ideas, but the tidy six-item list used in teacher trainings and studios today was distilled and popularized by later generations of teachers to make his approach easier to teach and remember. Because of this, you'll sometimes see slightly different wordings or a fifth, sixth or seventh principle added, depending on the school of training behind a given studio or teacher.
In practice, the six ideas are still a fair, honest summary of what you're aiming for in a session:
Concentration — bringing focused attention to each movement rather than moving on autopilot.
Control — moving deliberately through a full range rather than using momentum.
Centring — initiating movement from the deep trunk and pelvic muscles often referred to as the "core" or "powerhouse."
Breath — coordinating inhale and exhale with the phase of a movement.
Precision — placing the body accurately rather than performing a rough approximation.
Flow — linking movements smoothly, once control and precision are in place.
At Align & Flow Pilates, this last pairing — precision and flow — is central to how sessions are taught: technique and alignment come first, and the smoother, more connected quality of movement is built on top of that foundation, which is the idea behind the studio's name, "Where Precision Meets Flow."
Classical Pilates vs. contemporary Pilates — what's the difference?
Both classical and contemporary Pilates trace back to Joseph Pilates' original system, but the two schools of thought differ in how they treat it.
Classical (or "traditional") Pilates treats Joseph Pilates' original repertoire, sequencing and equipment as a complete system. The instructor's role is to transmit that system faithfully rather than change it, using only the original types of apparatus he designed and patented, in the order he taught them (Power Pilates).
Contemporary (or "modern") Pilates treats his original work as a strong foundation rather than a finished product. Contemporary programs often modify exercises, change the order they're taught in, and incorporate current ideas from physical therapy and movement science, sometimes alongside modern props like foam rollers or resistance bands (Power Pilates).
Neither approach is "correct" and both descend from the same source; the difference is mainly philosophical, and many studios — including boutique studios like Align & Flow — draw on both classical technique and contemporary teaching methods rather than adhering strictly to one lineage.
Classical Pilates | Contemporary Pilates | |
|---|---|---|
Philosophy | Original repertoire treated as a complete system | Original repertoire treated as a foundation to build on |
Sequencing | Fixed order, taught as designed | Adapted to the individual client and session goals |
Equipment | Original apparatus only | Original apparatus plus modern additions (e.g., foam rollers, resistance bands) |
Mat Pilates vs. equipment (reformer) Pilates
Mat Pilates uses your body weight on the floor, needs little to no equipment, and is often taught in small groups. Reformer Pilates uses a spring-loaded machine that can add resistance, assist a movement, or add instability to make an exercise more challenging, which allows for more precise adjustment to an individual body. Many people do both, since the two formats train similar principles in different ways. For a full breakdown of what a reformer session involves and how it compares with mat work, see our guides to reformer Pilates and reformer vs. mat Pilates.
Who is Pilates for?
Because sessions can be adapted — through the choice of exercises, equipment settings, and range of motion — Pilates is taught to a wide range of people, from complete beginners to competitive athletes, and is commonly adapted for pregnancy and specific posture concerns. It is not a single fixed workout, so the right starting point depends on your body, your goals and any conditions you're managing. If you're weighing whether it's a good fit as a first-timer, see Is Pilates Good for Beginners? If you're pregnant and wondering whether it's safe, see Pilates During Pregnancy: Is It Safe? And if your main interest is posture, see Can Pilates Improve Your Posture?
People also come to Pilates for reasons beyond any single condition — general strength, body awareness, recovery from a more intense sport, or simply wanting a workout that also asks for mental focus. A broader look at what the research actually supports across these goals is worth its own dedicated article, which we'll link here once it's published.
What does a Pilates session actually feel like?
A typical session is quieter and more deliberate than many group fitness classes: cueing is detailed, pace is controlled, and instructors often give hands-on or verbal corrections to alignment. Breath is cued alongside movement rather than left to happen automatically, and you'll hear specific instructions about where to place your ribs, pelvis or shoulder blades rather than a general "go." It's normal to feel muscles working in places you don't expect, particularly through the trunk, and it's common to feel fatigued through the core and stabilizing muscles without the class ever feeling like a cardio workout. For a full walk-through of what happens from arrival to the end of a first class, see our full walk-through of what happens during your first class.
A note on common myths
A few claims about Pilates circulate widely but don't hold up under scrutiny.
"Pilates lengthens or elongates your muscles." This isn't possible: muscles attach to bone at fixed points set by skeletal anatomy — a basic principle of human anatomy, not a claim resting on any single study — so no form of exercise, Pilates or otherwise, permanently changes the length of a muscle. The lean, long appearance some regular practitioners develop reflects a combination of modest strength gains, improved posture and alignment, and increased flexibility or stretch tolerance, not longer muscle tissue.
"Pilates (or any exercise) can spot-reduce fat from one area." A systematic review and meta-analysis of 13 studies and 1,158 participants that compared trained versus untrained limbs found a pooled effect size of essentially zero for localized fat loss from targeted exercise. Fat loss happens body-wide, through overall energy balance, not by working one area harder (Ramirez-Campillo et al., 2021, Human Movement).
Frequently asked questions
How long is a Pilates session?
Session length depends on the format and studio. At Align & Flow Pilates, a Small Group Pilates Class runs 55 minutes, a private 1:1 session runs 1 hour, and the Posture Assessment + 1:1 Pilates Intro runs 1 hour 15 minutes to allow time for an initial assessment.
Is "Pilates" a trademarked name?
No. In 2000, a U.S. federal court ruled that "Pilates" is a generic name for a type of exercise rather than a brand, so any studio or instructor can describe their classes as Pilates (Pilates, Inc. v. Current Concepts, 2000). What sets one studio apart from another is the quality of its teaching, not the name.
Should I start with mat classes or reformer sessions?
Either can be a reasonable starting point, and the better choice depends on your goals, budget and whether you want spring-assisted resistance from day one. See our detailed mat-versus-reformer breakdown for a full comparison.
What exactly happens on the reformer?
The reformer is a spring-loaded bed-like machine that can add resistance to a movement, assist it, or make it more unstable and challenging, depending on how the springs are set. For a full explanation of how it works, see how reformer sessions work.
Working on your foundations with us in Markham
If you're new to Pilates and want a clear, personalized starting point, the Posture Assessment + 1:1 Pilates Intro gives you a private introduction to the method built around your own body and goals, right here in Markham. If you'd rather start in a class setting, our Small Group Pilates Class is a low-pressure way to experience the method alongside others. Comparing studios across Markham and York Region before you commit? Our guide, How to Choose a Pilates Studio: 12 Things to Look For, walks through what's worth asking. You can see current openings and book either option at alignandflowpilates.com/book-online.
Sources
Joseph Pilates. Wikipedia. https://en.wikipedia.org/wiki/Joseph_Pilates
Watson, Sara Kiley (2025). "Pilates Started in a WWI Internment Camp." Popular Science. https://www.popsci.com/health/how-pilates-started/
Pilates, Inc. v. Current Concepts, Inc., 120 F. Supp. 2d 286 (S.D.N.Y. 2000). CourtListener. https://www.courtlistener.com/opinion/2499620/pilates-inc-v-current-concepts-inc/
"What Is the Difference Between Classical and Contemporary Pilates?" Power Pilates. https://powerpilates.com/learn/what-is-the-difference-between-classical-and-contemporary-pilates/
Ramirez-Campillo R, Andrade DC, Clemente FM, Afonso J, Pérez-Castilla A, Gentil P (2021). A proposed model to test the hypothesis of exercise-induced localized fat reduction (spot reduction), including a systematic review with meta-analysis. Human Movement, 23(3):1-14. https://doi.org/10.5114/hm.2022.110373
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