Begin sitting on the first step with your hands on either side of you, shoulder-width apart and flat on the stair. Your fingertips should be right on the edge or slightly off the stair, pointing forward. Place your feet hip-width apart about two to three feet from the bottom step, flat on the ground with your knees bent.
Slide your butt forward until it's just off the step. Keep your arms straight but not locked.
Extend and lift your right leg off the ground with control while simultaneously reaching toward your right toes with your left hand. Keep your core pulled toward your spine and your hips lifted throughout the movement.
Set your right foot and left hand back down, then repeat on the other side. This counts as one rep.
Complete for two sets of 12 to 15 reps, resting for 45 seconds between sets.