Why You Shouldn’t Do Sit-Ups

In the last years crunches became the preferred ab exercise instead of sit-ups. Here is why exactly you shouldn’t do sit-ups, especially if you are training for a six-pack.

Your Stomach Muscles

Those muscles that make up what people call the “six-pack” or “washboard abs”, are the topmost of a whole group that resides in this area. Beneath them are many more, collectively called the “hip flexors”.

The difference now between a crunch and a sit-up is that the crunch works those visible muscles, while when you do a sit-up, most of the work comes from those deeper muscles:

The Mechanics Of The Sit-Up

Research at the University of Waterloo shows the amount of force in Newton (“N,” simplified the force necessary to accelerate one kilogram one meter per second) that the traditional sit-up generates is about 3,350 Newtons of compressive force on your spine. That’s about what the National Institute for Occupational Safety and Health (NIOSH) says is the limit where you’re at risk for lower back injury risk.

Doing sit-ups often and in high volume puts forces on your spine that exceed the NIOSH occupational safety recommendations, because of the risk of disc degeneration and possible herniation.

But Shouldn’t You Train Your Hip Flexors?

It isn’t per se wrong to train your hip flexors, They have important tasks in stabilizing your lower back and moving the legs. But if your goal is training your abs and you do sit-ups, you are doing the wrong exercise.

Did I convince you about crunches? Here is how to do them correctly!

Picture courtesy of Sylvia McFadden.