For about four weeks after giving birth, you may not be able to resume a full workout schedule.However, with your doctor’s go-ahead, you can theoretically start certain exercises the day after delivery, if you’ve had a vaginal delivery without complications.Exercise post-pregnancy will help you recover more quickly and get back in shape. It will also help you feel more in control, at a time when that sense may be in short supply.  If you’ve had a C-section, your doctor will likely recommend a much longer waiting period before you’re cleared to begin exercising.Start with walking and light stretching. Kegel exercises (tightening the muscles that control urine flow) are also great. Together, this program concentrates on tightening your core—primarily your abdominal muscles and the ones in your lower back.When you’re pregnant, the abdominal muscles stretch (no kidding!) to accommodate the growing fetus. This decreases back stability, due to the stretching of the muscles. Hormones that cause your cartilage and ligaments to relax only magnify this effect. This may lead to diastasis recti, when the rectus muscles (that run lengthwise down your abdomen) pull apart because of the large uterus distending the belly wall.How do you know if you have separation? Lie on your back with your knees bent and feet flat on the floor. Pull up your shirt so that you can see your abdomen. Slowly curl your shoulders and head up off the floor. If you see a bulge or ridge form down the center of your abdomen, you have separation.You can also place your fingers lengthwise along the center of your abdomen and navel. Just barely lift your shoulders and head, and feel for a crevice or dip running lengthwise down the center of your abdomen. If one, two or three of your fingers can fit width-wise into this gap, you might have mild to significant separation. This separation leads to back pain over time.