Which muscles are used in crunches?

The crunch is one of the most popular abdominal exercises. When performed properly, it engages all the abdominal muscles but primarily it works the rectus abdominis muscle and the obliques . It allows both building six-pack abs, and tightening the belly.

Crunches, also known as abdominal crunches, are a core exercise designed to target your abdominal muscles—specifically your rectus abdominis (the six-pack muscle) and your obliques . Perform crunches by lying face-up with your feet hip-width apart.

While crunches exclusively workout your abdominal muscles, a sit up is a slightly more intense exercise that strengthens your hip flexors, abdominal muscles, chest, neck, lower-back, as well as the muscles in your lower-legs .