You've spent the nine months of your pregnancy eating right and exercising carefully, but after the birth of your child, you still look, well, fat and out of shape. Where do you go from here?

Doctors say it takes up to six weeks for the body to shed the immediate effects of pregnancy and to recover from the demands of childbirth. "Labor is intense physical exercise," says Ralph Hale, chairman of the department of obstetrics and gynecology at the University of Hawaii School of Medicine. "You expend a lot of energy."

Aside from often overwhelming fatigue, pregnancy and childbirth may have left you with a stretched and sagging abdomen and loose pelvic muscles. For women who got used to the feeling of a tight abdomen during their pregnancy, it can be quite a shock. And the level of progesterone, which climbed during pregnancy to keep joints and their protective ligaments loose and soft, will need to drop back to prepregnancy levels. If you've had a Caesarean section, recovery time will be slowed by the surgery.

It's best to check with your obstetrician on guidelines for postpartum exercises, but doctors generally advise women to take things very easy for the first two or three weeks after a vaginal birth and two to four weeks after a Caesarean. They recommend against vigorous exercise, such as jogging or aerobics, in order to allow the body to recover from pregnancy and labor.

But there are slow, gentle exercises that can be done in the first couple of weeks to boost healing and prepare your body for even more vigorous activity.

Elizabeth Noble, founder of the obstetrics and gynecology section of the American Physical Therapy Association and author of "Essential Exercises for the Childbearing Year," says physical recovery from pregnancy and childbirth starts in the first few days with gentle movements to shorten the stretched abdominal and pelvic muscles.

"If you don't go through the initial shortening, the muscle very quickly begins to think that the lengthened state is normal," she says.

Two useful exercises to shorten stretched abdominal muscles are head raises and abdominal breathing. For head raises, lie on your back and raise your head several times. Noble suggests setting your baby on your stomach and then raising your head to talk to him or her. For abdominal breathing, lie on your back or side with knees bent. Breathe in through the nose, letting the abdomen expand, and then blow the air out through the mouth slowly and forcibly, pulling in the abdominal muscles.

To shorten and strengthen the pelvic muscles, firmly tense the muscles around your vagina and anus and hold for five to 10 seconds. Slowly release the muscles and relax for several seconds. Repeat. Gradually build up to 25 to 50 repetitions a day. You should be able to interrupt your flow of urine within three weeks, Noble says. Start the exercises right in the hospital, within 24 hours after birth. "You will be amazed at what you can achieve during your brief hospital stay," she says in her book.

Repeat the exercises a few at a time and often. If you've had a Caesarean, you'll probably need to do them for a few days longer than if you had a vaginal birth.

As you feel stronger, Noble says, add more strenuous strengthening exercises, such as leg slides and abdominal curl-ups. To do a leg slide, lie on your back, knees bent, pelvis tilted backward and, sliding on the heels, slowly stretch your legs straight out. To do a curl-up, lie on your back with knees bent and pelvis tilted back. Bring your chin to your chest and, as you breathe out, fold your upper torso forward about eight inches and then slowly back down. As you get stronger, you can make the exercises more challenging by folding your arms across your chest or putting your hands behind your head.

After two to four weeks of shortening and strengthening the abdominal and pelvic muscles, it's time to tackle the rest of the body. But Raul Artal, associate professor of obstetrics and gynecology at the University of Southern California, notes that a woman can't simply return to her regular prepregnancy routine once the child is born. "Pregnant or nonpregnant, if someone interrupts physical activity for (even) 10 days, he or she is 'detrained,' " he says. "To reverse that status to a fit condition, one has to spend approximately three months."

Because it can take a while for the level of progesterone to fall, Artal tells his patients to avoid ballistic movements -- jumping, hopping, twisting, bouncing and running -- and activities that require such movements, such as tennis, weight-lifting, skiing and ice-skating, for at least six weeks. He also recommends avoiding repetitive movements, such as aerobics with lots of repetitions. He warns that jerky or repetitive movements can damage, sometimes seriously, joints and ligaments that are still soft and loose from the elevated level of progesterone.

Instead, Artel suggests, women should start off by walking, build up to race-walking and then into light jogging. Warming up and cooling down are particularly important, he says, but he warns against excessive stretching ("ballerina-type of stretching"), which, again, can damage softened ligaments and loose joints.

Hale notes that women who are breast-feeding need to watch their fluid intake because they're more apt to become dehydrated. Keep an eye on the color of your urine, he says. It should be a pale yellow; if it gets darker, boost your liquid intake.

As soon as you've regained your original strength, you can resume your normal activity, Artal says. How long that takes depends on the woman, but he says that if you've had a Caeserean delivery, it will probably be three months before you can engage in any significant form of exercise. One thing to keep in mind, he says, is: "It's not a test you have to pass. Many women are disappointed that they can't jog the six miles they used to before pregnancy."

Noble warns that you should avoid running or jumping if you feel any sensation of heaviness, dragging or pressure around the pelvic area. Instead, concentrate on pelvic exercises in order to build those muscles back up.

There are at-home postpartum exercise video programs, including a postnatal exercise program from the American College of Obstetricians and Gynecologists. Locally, various hospitals and some exercise studios offer postpartum exercise classes.

Of course, for most women, the biggest problem is finding the time and the energy to lace up the jogging shoes or pull on a leotard while caring for a demanding newborn.

Hale encourages his patients to get back to exercising as soon as they feel strong enough. "It's awful easy to say, 'No, I'm too busy,' " he says. "Then, next thing you know, two to three years have gone by."