If you begin to arch the back while doing a standard plank, it means you don't quite have the strength yet. Don’t worry: Plenty of my clients struggle with this. When your muscles fatigue ...

Why? "This variation looks a lot like a standard plank but involves rocking back and forth," Long explains. "It's great for strengthening your core and also your shoulders." Abbi Henderson is a ...

"Side planks are amazing for obliques and intercostals," Michaels says. These are the muscles between your ribs. This is the same idea as a standard plank, but you're facing the ceiling rather ...

This workout series created by physical therapists will improve your quality of life a quarter hour at a time.