Begin lying flat on the ground with your arms and legs spread wide and fully extended, forming an "X" with your body.
Pull your core tight as you lift your right arm and left leg, crunching upward to tap your left toes with your right hand (or get as close as you can.) Keep your left arm and right leg extended and flat on the ground.
With control, lower back down to the starting position.
This completes one rep. Repeat for 15 reps, alternating sides.