Side Plank Pose: Lie on your side with your elbow directly beneath your shoulder. Place your top hand on your top hip. Stack your top leg on the bottom leg. Lift your hips off the ground and engage your abs as your elbow and bottom leg support you.
V-Sit with Medicine Ball: Get in the V-sit position—balancing on your buttocks with your legs lifted and crossed, upper body lifted as well. Take a 5-pound medicine ball and hold it in your hands as you slowly use your abdomen to twist from side to side, keeping the V position.