Start standing, feet hip-width apart. Step your left foot back on a diagonal and reach your arms up and to the right. Tighten your core and drive your left knee toward your torso as you pull arms down toward left knee (as shown). Repeat quickly for 30 seconds; then switch sides.
2. Side Plank Leg Lift
Start in a side forearm plank, with your right elbow directly underneath your shoulder. Lift hips away from the ground and raise your left hand toward the ceiling. Now slowly lower your right hip to the ground, keeping the left leg stacked over the right. Drive your left elbow to your waist and lift your left leg 6-12 inches above your right (as shown). Lower leg to complete 1 rep. Do 30 reps; then switch sides.
3. L Crunch
Start seated with the legs extended in front of body. Raise your right leg to 45 degrees and grab behind your right calf or thigh. Engage your core and bend right knee toward torso (as shown), then release and extend the right leg long again to complete 1 rep. Keep your chin off your chest and your gaze high and long. Do 30 reps; then switch sides.