Absolutely Everything You Need to Know About Planks

With plank jacks, you get the core recruitment of planks, plus the heart-pumping cardio aspect of jumping jacks. If jumping is too much, you can also step your feet in and out.

• Start in a plank position with your shoulders over your wrists, core engaged, and feet together.
• Like the motion of a jumping jack, jump your feet out wide and then back together. Try to keep your pelvis steady, and don't let your hips rise toward the ceiling or dip toward the floor.
• That's one rep. Do three sets of 20 reps, resting for 30 seconds to one minute between sets.