Begin in plank position with the arms and body straight, shoulders over the wrists. Keep the core engaged. To modify, go down to your knees.
Bend the elbows behind you and lower your chest to the floor. Keep your upper arms tight to your body so your elbows are against your ribs on both sides.
Straighten the arms, coming back to plank position. This counts as one rep.
Complete for a total of five reps if you're on your toes (as pictured) or 10 reps if you're modifying on your knees.