Studies show that there are many benefits of an exercise program for the pregnant woman. Besides improving muscle tone, reducing weight gain, and improving cardiovascular fitness, studies also show a reduction in episodes of low back pain and other musculoskeletal complaints. Keeping fit with regular exercise during pregnancy also helps improve flexibility, posture and body mechanics which can further reduce incidence of injury or low back pain, a very common pregnancy complaint. Exercise can be a stress reducer, improves mood, reinforces the principles of deep breathing, and promotes post exercise relaxation. Pregnant women who exercise also have more restorative sleep patterns. Regular exercise can help prevent or treat problems associated with gestational diabetes, hypertension, and preeclampsia. Women who exercise throughout their pregnancy can have fewer complications of labor and delivery, shorter second stage labor, decreased need for medical intervention such as an induction, cesarean, and anesthesia. After labor and delivery women who have exercised during their pregnancies have shorter hospital stays and are better able to cope with pain levels during recovery.