When you do a standard sit-up or crunch, you are forcefully flexing your lumbar spine (lower back) into the floor. This creates a "hinge" effect that puts immense pressure on your intervertebral discs—essentially like squeezing a jam donut until the filling starts to leak.



To save your spine, we use the McGill Crunch (or McGill Curl-Up), named after Dr. Stuart McGill, the world’s leading expert on spine biomechanics.

Why the McGill Crunch Wins

Traditional sit-ups prioritize "the burn" at the expense of your discs. The McGill Crunch prioritises stiffness and stability.

Zero Lumbar Flexion - Your lower back stays in its natural, neutral curve.

Disc Protection - It prevents the "posterior shear" forces that may cause a slipped disc

Functional Strength - It trains the rectus abdominis and obliques to stabilise the torso, which is their true job in daily life.

How to Perform the McGill Crunch

Follow these steps to ensure you’re protecting your back while building a bulletproof core.

Set your position

 Lie flat on your back on a firm surface.

Leg Position

:Extend one leg straight out and bend the other knee, placing that foot flat on the floor. This "asymmetric" leg position locks your pelvis in a neutral position, preventing the lower back from flattening.

Hand Placement

Slide your hands under the natural arch of your lower back (the lumbar spine). Your hands act as a "pressure sensor" to ensure your back doesn't crush down into the floor.

Lift

Imagine your head and shoulders are resting on a scale. Slowly lift them just an inch or two off the floor.

Note: Do not tuck your chin or bend at the waist. Your head, neck, and shoulders should move as one solid unit.

Hold

Maintain this "micro-lift" for 10 seconds while breathing deeply.

Descent

Slowly lower back down. Complete your reps, then switch which leg is bent.