Day no. 19 – One-Legged Reverse Plank Bridge. Begin seated with your hands behind you, fingers pointed away.
Press the heels of your feet and hands into the ground as you raise your pelvis off the floor until it is in line with your shoulders and knees. Raise the right leg into the air. Keeping the arms straight, lower your pelvis toward the ground, then lift it back up to complete one rep. Try completing 3 sets of 20 reps for each leg.