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 ...

Why one trainer calls the plank variation "no joke." ...

Add Yahoo as a preferred source to see more of our stories on Google. While vanity muscles are nice, building a strong, stable base is crucial for all of your other gym and athletic goals. "Planking ...