Crunches is it true?
Q. A trainer recently told me I should stop doing crunches because they are bad for the low back. I’ve heard this before, but is it actually true? - Andrew James, Los Angeles, CA
A. Unfortunately, Andrew, it is. The problem, however, lies not with the exercise itself, but with the issue of lumbar flexion. Low back specialist Dr. Stuart McGill has shown through his laboratory research that a sit-up places approximately 3500 Newtons (386 lbs.) of pressure on the lumbar spine, and that repeated cycles of lumbar flexion and extension cause damage to intervertebral discs. Over time, the disc breaks down until you have a full blown herniation. The act of crunching also shortens the rectus abdominis and reinforces bad posture, while EMG studies show more muscle activation occurs with core stabilization exercises than crunches anyway. So, why not get the most bang for your buck while minimizing risk?
Filed under: Ask FitnessMash
