After having this conversation at least every other week in the clinic, it is time to write it down. I HATE SIT-UPS. Now, I know you are rolling your eyes and shaking your head thinking “No one likes sit-ups.” However, I bet that our reasons for hating sit-ups are very different.
As a physical therapist, I spend my most of my day teaching people how to build their abdominal strength. Trust me, I do not have one person performing sit-ups. Many of us equate six pack abs and strong stomach muscles with countless rounds of sit-ups; I am here to debunk that myth.
The Sit Up
To perform a sit-up, you start by either lying flat with your legs straight or lying flat with your knees bent and planting your feet on the floor. Then, you forcefully contract your stomach muscles, bending through your spine and hips to pull your upper body from the floor to fully “sit up.” This old school exercise was coined as a gold standard for an abdominal strengthening and an endurance building exercise about 60 years ago (1). However, as time has passed, we have learned this exercise is not what we once thought.
We have learned that flexing (bending) through our spine places excessive pressure on the discs in our back. One research experiment by Nachemson and Elfstrom determined that as little as 20 degrees of spinal flexion increases the pressure through our lumbar (low back) discs by 30%. As your spine continues to flex through the motion of the sit-up, the pressure on your discs reaches upwards of 150% (2). Now perform three sets of ten repetitions with those daily sit-ups and the discs in your back have been subjected to a beating.
When your abdominal muscles are weak (and let’s face it, most of ours are), your body will find a way to “cheat.” Our body is excellent at recruiting other muscles to aid in a movement which is too difficult. In the case of the sit-up, your hips flexors (strong muscles in the front of the hip and core) will kick in (1). Unfortunately for your spine, over-activation on the hip flexor can cause hyperextension at the spine. This hyperextension accentuates the lordosis (curve) of the low back, which actually can DECREASE your overall core strength. YIKES.
Do this instead
This isn’t an excuse for you to ditch your abdominal strengthening routine altogether. We need strong abdominal muscles is to keep us mobile and injury-free during our daily activities. That means you want your stomach muscles supporting your spine when you are bending, lifting, or carrying things. Think of the position you are in with all of those activities… You are standing, with your spine (hopefully) straight. So strengthening the stomach by forcefully flexing (or bending) the spine doesn’t make sense.
Swap out those repetitive bending sits up for a straight spine with a plank. Planks are the perfect exercise to stabilize your core for when you really need it: during your day to day life. A plank is performed with you on your forearms and toes, keeping your back straight and holding that position. Modified planks (which I recommend for those new to planks) is performed on your knees and forearms.
Just like with any exercise, proper form and difficulty level are key in accomplishing our goal. A stable spine can maintain that planking position for sixty seconds. For full instructions on how to build yourself up that sixty-second mark and to ensure you have proper form, check out THIS ARTICLE .
Please swap out the old school sit ups and replace them with a plank routine. If you haven’t been doing ANY abdominal strengthening, today is a great day to start! Your back, neck, hips, knees, and belly will all thank you!
References
1. Nachemson, Alf, and G. O. S. T. A. Elfstrom. “Intravital dynamic pressure measurements in lumbar discs.” Scand J Rehabil Med 2.suppl 1 (1970): 1-40.
2. Britton, Samual, and William Vincent. “Evaluation of the Curl Up: A Substitute for Bent Leg Sit Ups.” Journal Of Physical Education and Recreation 51 (1980):
