Experts differ on when it's okay to start a postpartum exercise routine. Many suggest waiting until six weeks postpartum, but research also shows that starting certain exercises much earlier than that can be both safe and beneficial.

Before you start doing any abdominal exercises, you'll need to make sure you don't have a diastasis, or separation of your abdominal muscles. These are common and will usually heal spontaneously, but if you begin exercising your abdominal muscles too hard before a separation heals, you may risk injuring the muscles.

To see if you have a separation, lie flat on your back with your knees bent, and place your left hand just above your bellybutton. Take a breath, and as you exhale, lift your head and shoulders off the floor and begin to pick your right hand up off the floor, too. You will feel your abdominal muscles tighten and will probably notice a gap between the muscles. If the gap is more than three fingers wide, hold off on doing crunches or sit-ups or other strenuous abdominal exercise until the gap shrinks to smaller than a finger's width.

Finding Time

In addition to physical constraints, one of the biggest obstacles to starting a postpartum exercise routine is finding the time for one. If you've gotten the idea that an exercise routine has to include hours of working out and you can't ever skip a day, you'll probably be even more intimidated. Don't worry — you don't have to be an Olympian to get back in shape. In fact, it's better to take it slow so your new body can adjust to the increased activity.

Any amount of exercise is better than no exercise at all. If all you can manage right now is getting out for a walk every other day, embrace it. If you go out for a jog with your baby and find that you have to stop every ten minutes to feed or comfort him, that's OK — exercise doesn't have to be continuous to count. Try not to judge your efforts or get frustrated if you don't feel like you're doing “enough.” As your baby gets older, it will become easier to squeeze in longer workouts.

If You're Breastfeeding

Contrary to what you may have heard, nursing moms can exercise safely. It's true that lactic acid, which is released by your muscles while exercising, can get into your breastmilk, but the lactic acid is safe for your baby. If you nurse your baby immediately after exercising, it may slightly change the taste of your milk, and some babies may reject the saltier flavor. You can avoid this problem by nursing your baby right before you exercise; by the time you feed him again, the lactic acid will most likely be gone from your milk. This will also help keep you more comfortable, since your breasts will be lighter while you're exercising.