Mermaid Stretch: How to Do the Pilates Side Stretch
The Pilates Mermaid Stretch is a seated side-body stretch that lengthens the waist, ribs and underarm while encouraging control through the pelvis and spine. You can practise it on a mat or use a Pilates ball for a more dynamic variation.
Use it as a gentle warm-up or a deeper side-body stretch, moving only as far as you can while keeping the pelvis steady and the breath comfortable.
What the Mermaid Side Stretch Does
The Mermaid opens and lengthens the side body — through the ribs, waist and underarm — while the pelvis stays stable and the spine stays long. It can be practised simply seated on a mat, or with a large Pilates ball for a more dynamic version of the same stretch. Both versions work on the same principle: the arm reaches up and over while the trunk stays controlled, rather than the movement coming from the lower back.
Seated Version
- Sit on the floor with both legs folded to one side (for example, to the left).
- Keep your sit bones grounded and your spine long — imagine your torso held flat between two sheets of glass, connecting pelvis and ribs rather than arching or collapsing.
- Rest your right hand lightly on the floor beside you for support as you sit upright.
- Draw your abdominals in and gently tuck your pelvis under — this is where the real support for the movement comes from.
- Keeping your left shoulder down and away from your ear, extend your left arm straight up and reach up and over in a long stretch, bringing the inside of your arm as close to your ear as feels comfortable, without hiking the shoulder.
- Let your breath flow steadily through the stretch, working with the reach rather than forcing it.
Using a Pilates Ball
- Roll one side of your torso over a large Pilates ball, balancing on the ball of one foot and the sole of the other.
- Keep the same pelvis-to-ribs connection as the seated version — flat and stable through the back and sacrum.
- Raise both arms gently overhead and clasp one wrist with the other hand.
- Extend up and over into the stretch, using the same shoulder and arm cues as the seated version.
- The ball adds a little more range through the side body, making this a more dynamic version of the same stretch.
Common Mermaid Stretch mistakes
- Lifting the shoulder towards the ear instead of keeping the neck long.
- Collapsing forwards or arching the lower back rather than moving directly to the side.
- Letting the pelvis lift away from the floor.
- Forcing a larger range instead of maintaining steady breathing and control.
Worth knowing: Move slowly and stop if anything feels sharp or uncomfortable — Mermaid should feel like a stretch, not a strain.
Try It in a Class
The Mermaid is one of many stretches you’ll come across in our Pilates classes at Embody. If you’re new to Pilates, our beginner classes are a good place to start.
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