You’re in a deep Pilates hold. Your inner thighs are burning. Your legs start to shake.

It can feel like something’s gone wrong. Like your body is reaching its limit too quickly.

But this is exactly where the work is happening.

As a Physiotherapist, this is one of the most common questions I get. And the answer is simple: your body is being challenged in a very specific, very effective way.

What’s happening when you feel the burn

In Pilates, movements are slow, controlled and sustained. That changes how your muscles are working.

Instead of short bursts of effort, your muscles are held under continuous tension. Blood flow is slightly reduced, oxygen becomes limited, and your body shifts how it produces energy.

This is where the burn comes from. It’s a sign that your muscle is working hard enough to create change.

Why your muscles start to shake

The shake is often the part that catches people off guard.

Your muscles are controlled by motor units - a nerve connected to a group of muscle fibres. When a movement becomes challenging, your body rotates through these units to sustain the effort.

At the edge of your capacity, that system becomes less smooth and that results in the shake. Your body is recruiting everything it has available.

The muscles Pilates is designed to reach

Pilates doesn’t just target the muscles you can see.

It’s designed to activate the deep stabilising muscles that support your body every day - your transverse abdominis, pelvic floor, spinal stabilisers and deep hip muscles.

These are not muscles you can access through speed or momentum. They respond to control, precision and time under tension.

When you remove momentum, every part of the movement has to be controlled. Every muscle has to contribute.

This is why Pilates is used in rehabilitation, in elite sport and in long-term performance training. It builds strength that is not just visible, but functional and lasting.

And over time, the same hold that once made you shake will feel steady.

Not because it’s easier, because you are stronger.

So the next time you’re in a hold and everything is trembling, here’s what I want you to hear: your deep muscles are working, your slow-twitch fibres are firing and you are getting stronger - right now, in this moment, in this hold.

The shake isn’t your body giving up. It’s your body giving everything.

If you want to follow a structured Program that’s designed to take you there, start with the LEAN Method.

Find your LEAN Method Program here.

Lilly