Exercise Library
McGill Curl-up

The McGill Curl-up is an isometric trunk exercise with reinforcement of a neutral lumbar spine and pelvic floor tension.
Lie on your back and bend one knee to place that foot flat on the floor while keeping the other leg straight. Place your hands under your lower back to support your natural lumbar curve. Take in a deep breath, tuck your chin slightly, and exhale as you tighten your entire trunk, including the pelvic floor, and crunch your abs to bring the bottom of your ribs toward your pelvis—this will be a minimal movement but should separate your upper and most of your mid-back from the floor and push your lower back down into your hands. Hold this position for 10-15 seconds, or for a series of 3-5 controlled breaths. Switch legs and repeat.
The McGill curl-up crunch is a good combination of continuous ab tension like an isometric hold and minimal motion for the abs while maintaining neutral spine curvature, and as a way to practice and reinforce trunk bracing. It can be used for a low-demand ab exercise to reduce difficulty or to allow very high repetitions, and it can be used in training preparation to get the trunk activated without excessive fatigue.
The McGill curl-up should generally be done for 2-4 sets per leg of 3-5 breath cycles or 10-15 second holds. This is a good exercise for training preparation, or in addition to heavier, lower-rep or more difficult ab work in a given workout or in a circuit.

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Luis Beza
June 7 2020
In the explanation of the execution, it says "push your lower back down into your hands".

-This will not make lose the lumbar curve?
-What kind of push should I feel in my hands?
The hands are there to prevent the loss of the lumbar curve. Pushing into them helps you focus on tightening the trunk.

Greg Everett
Luis Beza
June 13 2020
First, thanks for the free content and for your free answers to our questions, I try to support this free content as much as my budget allows me.

I pushed my lumbar spine against my hands and I could feel tighter on my abs.

I was playing around with this movement and used an AbMat. The difference was that by raising my upper back and pushing the AbMat with my lower backs (as if it were my hands) I went from an extended position of the thoracic spine, to a neutral position of the thoracic spine, and the isometric contraction was to try to maintain that neutral position of the spine.

When I don't use the AbMat, lying flat on the ground, my thoracic spine is neutral and when I lift my upper and middle back, I move to a flexed thoracic spine position.

The goal is to try to maintain neutral lumbar spine with flexion of the thoracic spine and tight abs?

Or try to maintain a neutral position of both, the thoracic spine and the lumbar spine (Using an AbMat)???

Is there a difference? Or am I doing the wrong job?
You're way overthinking this... tighten the abs as hard as you can and let that lift your body as it does - don't try to elevate the chest/shoulders/head specifically - they will lift as needed. You might imagine "shortening" your trunk.

Greg Everett
Luis Beza
June 15 2020
I am always trying to reinvent the wheel! Everything has become clear! Thank you coach!
Bob Olinger
March 25 2021
Is there a disadvantage to raising the extended leg slightly, while doing the crunch?
Fine as long as you're able to maintain the same lower back position, i.e. you're not allowing your back to extend again.

Greg Everett