Heather Milton, a senior exercise physiologist at NYU Langone Health, does not recommend sit-ups or crunches for building your core because they put your spine through unnecessary stress. Following is a transcript of the video.
Heather Milton: Going into exercises like crunches is putting your body in spinal flexion, rather than maintaining a neutral spine. There are many ways to strengthen your core. What we usually call the core are the abdominal muscles that support the spine. Our bodies should usually be in a neutral position in terms of the spinal alignment.
We like to try exercises, rather than doing a lot of crunches that will continue to put flex on your spine and that can actually put stress on the vertebrae as well as the discs that are between each vertebrae. We give exercises like planks to maintain a neutral position and really activate the muscles to support that neutral position and improve it.
There are many different muscles that contribute to your core, and the plank exercise actually does activate a lot of different core muscles. Not only just the six-pack abs — which is your rectus abdominis — but your transverse abdominis and your obliques. So this exercise is great for functional strength, not necessarily to build a six-pack through your rectus abdominis muscle, but to really be able to stabilize your spine and maintain a good, strong core.
Mostly if you’re trying to do exercises to improve the six-pack abs, crunches do work for that. But there are also different exercises you can do. I recommend doing hanging leg raises rather than doing the crunches, because you are putting less stress on your vertebrae when you’re doing the leg raises versus the crunch.