It’s All About Function
Sit-ups or crunches? Chin ups or bicep curls? If you’re a CrossFitter, hopefully you know the answer to these questions… but why? Why choose a sit-up or a chin-up over these alternatives?
Have you ever in your life tried to sit up out of bed or get up off the floor and only use your abs? Or how about lifting up a bag off the floor – try to do it with just your biceps. The thing is, neither of these tasks are possible, your body simply can’t naturally move this way. It functions as one, synergistic unit, not as a multitude of small, isolated parts. So when you go to sit up out of bed, your brain activates every muscle it needs to accomplish this task, among them, the rectus femoris, illiopsoas, rectus abdominis, transverse abdominis, internal and external obliques, serratus, various muscles of your neck, etc. As it happens, these are also the muscles that you use in a sit-up – which is what we mean when we say that a movement is “functional.”. In contrast, a crunch isolates your upper rectus abdominis, nothing else.
So the next time someone asks you why you do sit ups instead of crunches… you’ll know the real answer – and can keep it simple by saying, “Its all about function and how our bodies naturally move.”