Once you've perfected the traditional plank and the shoulder tap, try this variation. The elbow plank with a rock reduces the stability of the position, which means your core strength is really going to have to kick in. When performing this core-stability exercise, try not to let your hips tilt or shift up or down.
- Start in an elbow plank.
- Lift your right foot about six inches off the ground (your big toe should be about in line with the heel of your grounded foot), keeping your pelvis parallel to the floor.
- Rock your entire body slightly forward, allowing your shoulders to move past your elbows.
- Return to center, lower your foot, and repeat on with the other foot lifted. That's one rep.
- Repeat for 30 seconds.
