Abdominal crunch

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 .

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.