“SO WHAT ABOUT CRUNCHES?”
Personal Training Question Number One
I get this question from many of my fitness clients at the end of their personal training or group coaching sessions. Somehow crunches are viewed as an essential part of fitness. Instructional DVDs are sold with an hour of abdominal exercises—I counted 12 different types of crunches and sit ups in one very popular infomercial product. In physical therapy, I get to treat the patients who in a valiant, but misguided effort to regain fitness launch into a series of crunch / sit up exercises only to wake the next day with searing lower back or neck pain. I was recently asked to e-mail my no crunches answer–so here we go.
Most fitness clients are already have earned a black belt in spinal flexion. Their thoracic and lumbar vertebrae are bent forward for many hours a day– sitting too much, driving too much, television too much. Most are proud at how easily they can fold the thoracic and lumbar spine over and “palm the floor”. The last thing they need is to pull the ligaments, discs, and joints of their spine into further flexion with crunches and sit ups.
Your Mother’s Eyes and Your Grandma’s Spine
As we age, our thoracic and lumbar spines tend to fall into a flexed over “crunched” position. Why would you want to accelerate the pace of this degeneration by performing activities that accentuate the slumped over forward flexed spinal posture of old age.
The Other Spot Reducing Exercise
Your abdominal muscles or “six pack” will not become more visible with lots of crunches, sit ups, rip twists, belly blasters, or any other targeted training. There is no such thing as spot reducing. The table push away is the best exercise to improve the visibility of any muscle. Unfortunately, it is the least utilized exercise in America.
A Little Kinesiology
The function of your abdominal muscles is not to create movement but rather prevent movement. They work with a team of other muscles to act as anti extensors, anti rotators, and anti flexor muscles. The six pack muscle or rectus abdominus makes up a portion of the cylinder of muscle that serves to support your spine in tall and stable position–not bend it forward. Think “movement preventers” and not “movement producers”. Crunches and sit ups train your abdominal muscles to do the wrong thing.
The Pros Don’t Use Them
I cannot think of any athletic activity that emulates the motion of a crunch or sit up. It will not improve your ability to run, jump, throw, or compete. The strength and conditioning coaches that get paid big money to make athletes more successful and keep them injury free do not use crunches or other repeated trunk flexion exercises in their programming.
Maybe Not Now, But Soon And For The Rest Of Your Life
Your lumbar spine hates combined flexion and rotation, and it really hates it if you throw in some compression from an exterior load like a medicine ball, weight plate, or kettlebell. Lumbar spine injuries are cumulative. The stresses build up until one day you bend over to pick up a pencil and your back “goes out”. Crunches and sit ups serve to accelerate the rate of accumulated spinal stress. I know you have a friend who does one hundred twisting, medicine ball crunches a day and has never had a problem. I have a friend who has smoked for twenty years and says he feels fine.
Michael S. O’Hara, P.T., OCS, CSCS