Start on floor in full push-up position, balancing on hands and toes, body forming a straight line from head to heels. Move feet slightly wider than shoulder-width apart.
Keeping hips level, lift left hand off floor and bend left elbow behind you to bring hand next to shoulder.
Return to start.
Repeat, this time rotating torso to right so that left elbow points up (as shown). Return to start to complete 1 rep.
Do 2 sets of 10 reps, alternating sides.