Between travel and dressing up in high heels, legs muscles are often tight around the holidays. Stretching daily will improve your flexibility as well as help you build strength. Target the back of your legs with this stretch: Lying on your back, extend your left leg and raise it until you feel a stretch. To protect your back and aid in keeping your hips from rolling, you can bend your right leg, keeping your right foot on the floor. Hold the stretch for 15-30 seconds. Switch legs.