This exercise from the BOSU 3D XTREME exercise library challenges core strength, stabilization and balance. Place two BOSU Balance Trainers next to each other and sit on the end of one dome with the knees lifted and feet off the floor. With both hands on the sides of the dome, angle the knees side to side in a “kayaker” motion for 10 repetitions. Then, lie back on the second dome and alternately lower one bent leg at a time until the toes touch the floor. Roll back up and repeat. Progress by lifting the hands and rotating the torso in opposition to the legs, then perform the leg drops with straight legs. For more challenge, increase range of motion of both movements. To subscribe to a full library of BOSU 3D XTREME exercises, visit www.3d-xtreme.com.