What It Works: Transverse abdominus and obliques. Lie on right side with right elbow under shoulder, forearm on floor for stability. Stack left foot on right foot. Raise left arm over head. B. In one motion, lift your hips to create a straight line down your left side. Lower your hips a few inches off the floor; do 10 to 15 reps, then switch sides. Why It Works: Strong obliques improve your stability in the saddle, letting you take on hairpin corners with more control and speed.