This no-movement exercise is one of the most reliable ways to measure core endurance, posture control, and spinal protection—making it a favorite among U.S. fitness professionals.

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 ...

Getting up from the floor without wincing. Carrying groceries without your back complaining. Standing tall through a long day without fatigue creeping in. These everyday moments reveal something ...