Plus, which move is more effective for strong abs.

Here's what the exercise is, which muscles it works and why crunches are so good for overall health.

When we think of core exercises, standard moves like situps and crunches are often a go-to. But working the side body is an important piece of a well-rounded core routine that is sometimes overlooked.

Exercises like dead bugs help lengthen and strengthen the hip flexors in a controlled position, which improves form and can help offset the effects of sitting too much, adds Dickinson. Lie faceup, ...