A physical therapist explains how a modified side plank with a clamshell strengthens runners’ core and hips to improve efficiency and reduce injury risk.

If you’ve ever tried them, you know side planks are challenging­—even more than regular planks. But they’re a critical move, says Keli Roberts, an exercise physiologist with the American College of ...

A staple of many core workouts, most runners will be familiar with the side plank exercise. But you may be surprised to learn that it's one of the best exercises you can do for working your deep core.