When you find out that you're expecting, your abdominal goals flip from keeping your tummy tight and toned to keeping your body strong and healthy for a successful labor. Although pregnancy seems like a good excuse to skip exercise, avoid the temptation -- the American College of Obstetricians and Gynecologists recommends at least 30 minutes of moderate-intensity exercise most days of the week, and that should include abdominal exercises.
Moms-to-be should focus on strengthening not only their abdominal muscles but also their entire core during pregnancy. Strong core muscles help prevent back problems and poor posture caused by a protruding stomach, make it easier to push during labor and speed up the recovery process.
Additionally, moderate strengthening exercises helps reduce the risk of abdominal separation. The rectus abdominis muscle is actually made up of two halves. Hormones can cause the vertical seam between them to soften, and as the baby grows, that seam stretches. If the abdominal area is weak, the seam can separate gradually or with sudden exercise. This can cause an increase in back pain, because the ab muscles are no longer controlling your pelvic tilt and maintaining your posture. Check for abdominal separation by lying on your back with your knees bent and feet flat on the floor. Drop your chin to your chest and raise your head and shoulders about 6 to 8 inches from the floor. Hold out one arm in front of you; with the other hand, check for a gap if you're in the first few months of pregnancy or a bulge if in the last three months.
Although you might be worried about the tiny embryo setting up shop in your uterus, it's safe during the first trimester to continue with your regular ab exercises -- with caution, of course. Avoid holding your breath while you exercise, and skip anything that might require a jerky or twisting motion, recommends the pregnancy website What to Expect.
At this point in your pregnancy, you can continue to do workouts lying on your back -- a no-no later on -- so try floor exercises such as the roll up. Lie on your back with your legs slightly bent and your feet flexed. As you inhale, lift your arms up toward the ceiling; on the exhale, lower them back over your head so they're stretched above you, but not touching the floor. Inhale again and curl your head, shoulders and arms off the floor; exhale and continue to curl, focusing on rolling up one vertebra at a time. When you reach the top, straighten your legs and reach forward toward your toes. Inhale and slowly roll back down to the starting position.
As your belly grows, it becomes harder and harder to exercise your abdominal muscles. Safety also becomes a greater concern; still, this doesn't mean you should neglect your abs entirely. At this point, avoid any exercises that require lying flat on your back, as this is the location of the vena cava, a large vein that runs along your spine and carries blood to the baby's heart. Significant time spent on your back compresses this vein, though up to five minutes can be safe as long as you don't feel dizzy or in pain.
Instead, work your abdominals with the plank exercise -- get on your forearms and knees so your elbows are directly under your shoulders. Push your knees off the floor so your body creates a straight line from your ankles to your head; avoid arching your back. Hold the position for one to two breaths, trying to work your way up to five breaths. If your abs aren't strong enough for a plank on the forearms, perform a plank in the pushup position, which is tougher on the shoulder muscles.
When you hit the third trimester, abdominal exercises might seem like a thing of the past due to a lack of mobility. Still, you can sit on a fitness ball when working or watching TV for a moderate abdominal workout. This lightweight piece of fitness equipment engages deeper muscles within your core, which can aid in keeping proper posture as your body changes and puts strain on not-often-used muscles. What to Expect recommends picking a ball made from burst-resistant material and inflating it to the right size for your height -- 55 centimeters if you're 5 foot, 3 inches, or under, and 65 centimeters if you're taller.