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 ...

Planks and jumping jacks are perfectly fine workout moves. But if you combine the two together, you can actually get an even better total-body workout. Meet: the plank jack! Plank jacks involve ...

Starting in a pushup position, making sure wrists, elbows and shoulders are in a line, jump your feet out to the sides simultaneously and immediately back to center. Repeat 12 to 15 reps.