PLANK WITH KNEE TUCK

Get in the plank position: Make sure your shoulders are directly over your elbows and that you’re on your toes with your feet about shoulder-width apart. Drive your right knee to your right elbow. Hold for two seconds, and return your right leg to the starting position. Mirror the same movement with your left knee, and repeat for three sets of 10 reps. As you reach your knee forward, your spine should round, creating abdominal flexion, which strengthens the core muscles, Roberts says.

DRAW-IN MANEUVER

Lie on your back with your knees bent and your feet planted on the ground. Pull your belly button toward your spine, leaving no gap between your lower back and the floor. Hold for 30 seconds, making sure to continue to breathe regularly. Repeat four times.

SUPINE KNEE LIFTS

Lie on your back with your feet planted on the floor. Place a folded towel or yoga block between your knees (not pictured). Squeeze the towel or block, exhale, and drive your knees upward toward your chest, lifting your lower back off of the floor as you do. Slowly release legs back to starting position, letting each vertebra return to the floor one at a time. Do 10 reps.