Both are Pilates. Both use the same principles: control, breath, alignment, precision. The difference is what you are working against — and it changes the experience far more than most people expect.
Mat Pilates, briefly
Mat Pilates uses your own body weight on the floor, sometimes with small props: a ring, a band, a soft ball, light weights. It is portable, cheap, and can be done in a village hall, a gym studio or your living room.
It is also, done properly, extremely difficult. Without springs to assist you, there is nothing to hide behind. A well-taught mat class is not the gentle option people assume it is.
Reformer Pilates, briefly
A reformer is a sliding carriage on rails, connected to springs, with a footbar and long straps. You can lie, sit, kneel or stand on it. The springs can make an exercise harder by resisting you, or easier by supporting you.
That dual role is the whole point, and it is the reason a beginner and an experienced mover can do the same class productively.
The practical differences
Feedback
The reformer tells you when you are cheating. If you lose control of your pelvis, the carriage judders. If one side is stronger, the carriage travels crooked. On a mat you can compensate quietly for years without noticing.
Load
Springs let you add real resistance, which means reformer work can build strength in a way that body weight alone eventually stops doing.
Assistance
Springs can also hold you up. Exercises that are inaccessible on a mat — because you cannot yet support your own weight in that position — become possible on a reformer straight away.
Range
The straps take your arms and legs further than you would take them yourself, under control. Most people get more mobility work from a reformer class than a mat class.
Cost
Mat is cheaper, almost everywhere. Reformer classes cost more because the studio has to buy and maintain ten machines and cap the class at ten people.
So which should you start with?
If you are completely new to Pilates and choosing between them, the reformer is usually the easier place to start — which is the opposite of what people assume. The machine gives you support, feedback and structure, and a beginner class has to explain the equipment, which means it has to go slowly.
Start with mat if you want the cheapest possible entry, want to practise at home, or already have a strong body-weight training background and want the challenge.
Start with reformer if you want strength as well as control, if you are rebuilding after a break and want support, or if you know perfectly well that you will not do this at home no matter how good your intentions are.
The honest answer: do both, eventually
They are complementary. The mat teaches you to own the movement without help. The reformer teaches you to load it. People who do both tend to be better at both.
But you have to start somewhere, and for most people walking into a studio in Shrewsbury for the first time, one reformer class will tell them more in an hour than a month of thinking about it.
