I love the man who wants to kill crunches

I can get a sense of personal trainers' knowledge about effective and safe core training with one simple test: do they include crunches in clients' program or in a class environment?

Whenever I try out new classes, watch fitness experts on TV, read fitness articles, if the crunch is there I know they haven't been following the #1 expert in spine biomechanics, Dr. Stuart McGill. If any fitness experts are reading this and don't know this name, it's time to familiarize yourselves with his work to get yourselves up to date.

I've heard him speak at conferences and even got to shake his hand once. Now Dr. McGill is going mainstream. In January 2010 Macleans published an article about him. Maybe personal training certifying organizations are going to start including his research so that the crunch will die die die.


Here's a short excerpt from the article:

After three decades of figuring how out the spine works, Stuart McGill has come to loathe sit-ups. It doesn’t matter whether they are the full sit-ups beloved by military trainers or the crunch versions so ubiquitous in gyms. “What happens when you perform a sit-up?” he asks. “The spine is flexed into the position at which it damages sooner.”

The professor of spine biomechanics at the University of Waterloo knows a thing or two about snapping spines. In his lab, McGill proudly shows off a machine that’s probably created more disc herniations than any other in the world. “We get real [pig] spines from the butcher and we compress them, shear them and bend them to simulate activities such as golf swings and sit-ups, and watch as unique patterns of injury emerge.” A disc has a ring around it, and the middle, the nucleus, is filled with a mucus-like liquid. Do a sit-up and the spine’s compression will squeeze the nucleus. On his computer, McGill shows how the nucleus can work its way out of the disc, hit a nerve root and cause that oh-so-familiar back pain. “From observing the way your total gym routine is performed, we can predict the type of disc damage you’re eventually going to have.”

I try to explain to my clients why crunches aren't functional. 95% of the population is in a slight forward head posture and in a permanent forward flexion position in the upper body. That means that the muscle fibres in the upper abs are dominant. A crunch emphasizes these muscle fibres that are already too strong in relation to the rest of the muscles in the torso. Furthermore, the crunch strengthens us even further into the posture we should be trying to correct. So not only are crunches bad for our backs but they also can make our posture worse by rounding us forward even more. Make sense? Aren't we constantly trying to stand up straighter instead of slouch? Why would we do a repetitive movement, sometimes even with extra weight, that is basically a lying down slouch?


When thinking about fixing alignment, posture and structural imbalances, we are trying to hit the muscles that are dormant and underdeveloped. Hey I'm not saying I'm innocent. I used to do crunches til the cows came home. But I try to maintain my curiosity and drive to constantly improve my knowledge and I ditched crunches years ago.

My go to exercises for developing core strength are the same as the ones Dr. McGill recommends because he's the man, the man who wants to kill crunches. But once I know people's cores have sound functional strength, we can really start playing around with core exercises that will blow your mind.

So next time you're interviewing a personal trainer, ask them one question to get a sense for their knowledge of proper core training, "are we going to do crunches?" If they say yes, especially if you have back problems, run away.

Jane Clapp