Why I Avoid Sit-Ups and Crunches

I hinted last week that sit-ups and crunches are not good exercises for strengthening your core, and if you’ll indulge me, I’d like to explain why.

1) They aren’t performed correctly
So many times I see people pulling on their head/neck to close the gap between sternum and knees (see picture below). What this does is initiate the motion from the front neck muscles, allowing them to be the dominant muscle group and the abdominals kicking in later (not to mention pulling the head farther in front of the body than it’s supposed to go).
                             
OR I see people tuck their feet under a couch or have someone hold their ankles (see picture below). This allows the hip flexors (the muscles that cross over the front of the groin area) to be the primary muscle that pulls the body off the floor.
                          
So in their pursuit of strong abs, these people have instead given themselves neck and low back strains. And don’t even get me started on the people who do sit-ups at lightning speed, as if trying to beat some unseen buzzer (increased momentum needs less muscle recruitment).

2) These exercises don’t match their purpose
Of the 4 different abdominal muscles (see last week’s post) crunches and sit-ups use the rectus abdominis and obliques since these are the muscles that move the trunk. It’s not guaranteed that the transverse abdominis and multifidus will activate in the correct way (especially if you have pain or have had surgery) since it’s not required for movement, only stability. Therefore, reasons like “I’m trying to strengthen my back” or “I want to improve my core” aren’t being met by crunches.

They will, however, train your body to repeatedly bend the spine forward, but you shouldn’t be doing that anyway. Anyone who’s taken an OSHA class should know you “bend the knees, not the back” when picking something up. We’re not supposed to bend forward to pick up objects because there’s a risk of straining the back—so why train it that way in the gym?

3) Increased abdominal pressure
When trying to bring the head down toward the knees during a sit-up it’s almost impossible to keep from internally directing pressure downward onto the back and pelvic area. If you have any kind of back injury or have had surgery this increase in pressure puts strain on weakened tissues beyond what they can tolerate. And if you are a woman from adolescence to post-menopause the increase in pressure onto a weakened pelvic floor can result in bowel/bladder incontinence or even organ prolapse. (More on the topic of the pelvic floor in a later post.)

All in all, there are so many other exercises that target core stability in a safer and much more effective way than either sit-ups or crunches. If you’re like me, you don’t have hours to spend at the gym working out; so what are some quick and easy exercises that will promote core strength? Tune in next week…