A plank is more difficult than it looks. You have to use all of your muscle groups, including your core, abs, arms, back, shoulders, glutes and legs. It’s normal to struggle to do a plank. Many of my ...

YOU PROBABLY THINK you know how to do a plank. The ab training staple is relatively simple, after all—boiled down to the basics, all you need to do is get down on the ground and hold in place.

Pilates pro Simone de la Rue demonstrates how to do a plank jack—aka the ultimate cardio and core-strengthening move—with proper form. A little known fact about planks: In addition to working nearly ...

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

As we're experimenting with more at-home workouts to keep ourselves healthy and happy outside of the studio, I wanted to look into improving one of the simplest total-body (but mostly core) exercises: ...