Crunches are the New Sit-ups
Melanie Clark Mogavero, RYT, CSCS
Sit-ups, for the ultimate “washboard abs” or “six-pack” men would call it, or performed, even as far back as Jane Fonda, for the sexy-flat midsection women coveted, were all the rage years ago. They were part of everyone’s abs routine, exercise video, and if you were lucky to have one, definitely part of you personal trainer’s program.
And you felt it…in your abs, that burning sensation every time you struggled to sit yourself up for one more rep, you can feel your midsection toning, firming, flattening…
Then some problems starting occurring, people starting running to their doctors with back pain, only to find out that their pain was due to a herniated disc. It then became common knowledge; in fact, I remember even in middle school, “sit-ups were bad for you back.”
This is supported by Michael Higgins, the director of athletic-training education at Towson University in Maryland. “Having a strong back, you will be happy to hear, means not doing sit-ups. Ever. “Sit-ups are not healthy for the back,” quotes Michael Higgins, the author of several prominent academic articles about back injuries in athletes. “They can severely compress the lumbar spine.”1
Basically, when the lumbar spine is compressed in that flexed position, the discs are forced outward, resulting in herniations.
So along came crunches, not the full sit up, you just come up a little bit, so it does not put that much stress on the spine.
Crunches were all the rage throughout the 90s!
Crunches, for the ultimate “washboard abs” or “six-pack”. At this time, even women wanted that 6-pack. Crunches were featured in every exercise video imaginable, “Abs of Steel” and “6-Minute Abs” and celebrities such as Cindy Crawford, and fitness guru Tony Little performed them in their videos. They were part of everyone’s abs routine, exercise video, and if you were lucky to have one, definitely part of you personal trainer’s program.
And you felt it…in your abs, that burning sensation every time you struggled to crunch yourself up for one more rep, you can feel your midsection toning, firming, flattening…. Hec, you could do so many of them now your neck hurt! So out come all sorts of apparatus to assist in these crunches to support your neck. These were great; you could rest your head, arms, and crunch away. In fact, I had the one marketed by Tony Little. Our abs got so strong that crunches became easy, quick. Then came the exercise or stability ball, do crunches on those, and it makes it even harder! Plus, your back is now supported under the ball! Or is it?
But uh oh, now we are starting to realize that the same thing that occurred with sit-ups is happening with crunches. The only difference is it happening much slower, so it is not easy to attribute the herniated disc to those crunches. It could be attributed to something else you did or have been doing, right? Herniated discs are overuse injuries or repetitive stress injuries. They do not occur immediately, they occur slowly, over time.
Take a look at the different position of the discs in the picture below. You can see how over time, repeatedly flexing and extending the spine while crunching with the force of your body weight can eventually cause the disc to herniate.
This issue was looked into closer by Dr. Stuart McGill, Professor of Spine Biomechanics at the University of Waterloo, who has been studying the spine for three decades. His latest research consisted of taking cadaver spines of pigs, compress them, shear them and bend them to simulate activities such as crunches, and watch the injury develop. According to his research, a crunch generates at least 3,350 newtons (the equivalent of 748 lbs) of compressive force on the spine. Wait, what? I will repeat, a crunch generates at least 3,350 newtons (the equivalent of 748 lbs) of compressive force on the spine. The U.S. National Institute for Occupational Safety and Health states that anything above 3,300 newtons is unsafe. 2
Therefore, crunches are unsafe, period.
Crunches are slowly being phased out workout programs, are replaced with exercises taken from yoga, which when done correctly, are extremely effective core or abs strengthening, back-friendly movements. According to Michael Higgins, “you need to activate and strengthen all of the muscles that circle the spine like a belt,”1 which yoga does.
Therefore, take this information and use it to your advantage. If you are doing crunches, you will injure your back, not might, will. It may not be tomorrow, but it will happen. If you have a personal trainer who is still making you do crunches, you might want to ask yourself if your trainer is obtaining their recommended amount of continuing education, and keeping up with the latest research, which EVERY professional has the obligation to do, whether you are a dentist or hairstylist. If your personal trainer or group fitness instructor are still training you as if it is the 1990s, its time to find a new trainer, who will bring you into the new millennium.
1. Reynolds, Gretchen. (2007). Twist and Ouch. New York Times on October 28, 2007
2. Treble, Patricia (2010). Macleans.ca, January 19, 2010.
