Yes, this is true.
If you want to train your “core” and crunches and/or sit ups are your go-to, you have definitely lost your way.
All you have to do is ask any experienced fitness or health professional and they will tell you, the best way to get flat abs (or anything close to that) is through food.
Sad, I know.
However, there are things that you can do to help recruit your abdominal muscles to strengthen and support you and crunches aren’t it.
And I will tell you why.
The reality is crunches have nothing to do with your core because they are focusing on the superficial muscles (the rectus abdominis). Crunches and sit ups are a flexion of the spine to help “crunch” the rectus abdominal muscles together and make them stronger – BUT they also make them bigger.
Well, if you think about it….do we perform bicep curls (a flexion movement) to create a flat bicep?
And there’s research too!
Stuart McGill, a professor at the University of Waterloo in spine biomechanics tells us that crunches recruit less than 20% of your rectus abdominis and overload your spine outside of healthy limits.
In other words, you are doing all of this hard work (with good intentions of course) to get less than 20% return AND you are putting yourself at risk for spinal injury!
So for all of those times that you are pulling on your head and killing yourself to do the “100 crunches a day” challenge; I ask you…..how’s it workin’ for ya?
The fact is, unless you have to perform a flexion movement repetitively over and over again, there is no reason to perform crunches as you are really wasting your time.
Instead choose movements like dynamic planks and other various core foundation exercises that recruit more than just your rectus abdominis, but your transverse (the deepest layer) and your obliques (middle layer) too!
But before you even do that, check out What is the Core Anyway? and start from the inside out!