"A strong pelvis means that you can hold sexual positions," Hays explains. "Especially those that involve swiveling and twisting." He recommends doing one set of 10 pelvic lifts every other day to exercise the muscles that attach to the pelvis and hips. Lie flat on your back with your knees bent and your feet flat on the floor. Take a deep breath, clench your abs and butt and lift your pelvis with your spine straight. Slowly and firmly suck in your abdominal wall and breathe. Hold that position for 10 seconds or more, and then relax.