Start in the plank position. You want your wrists directly under your shoulders, and your feet set shoulder length apart from one another.
Notes on Form:
Make sure your back is flat! To help do this, tighten your abs, like your belly button is pressing back to your spine, and tighten your glutes. Remember it's called a plank because you want to look like a straight plank of wood from head to feet! Also, keep your shoulders back. This means keep your shoulders away from your ears, and activated, like you are holding an orange between your shoulder blades, but not tight enough to juice it.
Bring your right heel towards your butt. As you do this motion, bring your left hand back to tap it. Slowly and with control, return back to starting position.
Repeat this motion, this time bringing your left heel up to your glutes to meet your right hand.
Always maintain tension in your core to keep your body still. You want to eliminate as much rocking between your shoulders as possible to get the most out this workout.
Do this exercise, alternating between each side, for one minute.