Planks are an excellent full-body exercise, particularly for the core and upper body. They are weight bearing through the arms and wrists, which is good for strengthening these bones. By adding shoulder taps, you challenge your core and arms even more. This exercise should only be performed by someone who can comfortably hold a 30 second plank.
Begin on the ground, on your hands and knees with hands shoulder-width apart.
Reach each foot back one at a time until you are in a full plank. From this position, bend the right elbow and touch your left shoulder with your right hand, supporting your upper body with the left arm only. Return the right hand to the floor and repeat with the left hand tapping the right shoulder. Return the left hand to the floor. Repeat, alternating from right to left arm while maintaining a steady plank position. Engage your core to keep your body as still as possible throughout this exercise.