Keeping Fit for a Healthy Pregnancy
Many pregnant women know that maintaining a moderate exercise routine and a nutritionally sound diet provide both short- and long-term benefits to the mother and baby. But routines and regimens that may be helpful during one stage of gestation may be detrimental during another.

That's what Hunter Clarke-Fields found. Before becoming pregnant with her second child, she led an active lifestyle. But when nausea and fatigue set in during the first trimester, she was forced to curtail her workouts.

"Somewhere around 13 weeks I started feeling better, so I eased back into my yoga, which I had stopped altogether, and brought my cardio exercises up to speed," she said, now 26 weeks pregnant.

Although nausea and fatigue may compromise women's exercise routines early on, these side effects usually subside by the second trimester. As the fetus grows, however, mothers may find certain positions and movements increasingly uncomfortable, tiring -- even harmful.

"By the beginning of the second trimester, women should avoid supine and inverse positions as these can restrict the baby's blood flow," said certified Pilates instructor Mara Raskin.

"During this time, the hormone relaxin also kicks in, making ligament looser and joints more vulnerable to injury. And as the belly expands, the body's center of gravity shifts and can cause stress on the lower back and pelvic muscles," she said.

At this point, Raskin suggests women focus on the upper and mid-back, shoulders and chest muscles.

"This will support their shifting weight, help maintain posture and strengthen the muscles that support the spine," she said. "Women should also strengthen the pelvic floor muscles by drawing them in and up with Kegal exercises."

Rose Willard does this. Now 14 weeks pregnant, the personal trainer has altered her routine to prepare for the road ahead.

"I start with a five-minute warm up on the elliptical trainer, followed by weight training -- using less weights and more repetitions than before -- to strengthen both my upper and lower body," she said. "I then do transverse abdominal exercises to stabilize my spine and end with another 15 minutes of cardio, making sure my heart rate doesn't exceed the recommended 140 beats per minute. To strengthen the pelvic floor and PC muscles, I also do Kegal exercises."

These days Clark-Fields is focusing more on back and abdominal muscles to ease back pain and prepare for labor.

"In addition to the back and ab equipment I use at the gym, I do a lot of balancing poses and planks to strengthen my abs and back. I also do cat stretches, downward dogs and some gentle side-to-side twisting," she said. "As the pregnancy has progressed I just listen to my body, and if an exercise doesn't feel right, I don't do it."

"Good idea," said Deborah Ehrenthal, MD, FACP, OB/Gyn specialist.

"If you're in doubt or feel discomfort, don't do it. Most important, if you experience bleeding or pain, stop and talk with your doctor. It may be completely unrelated, but it should be checked out," she said.

During exercise wear loose, layered clothing and a supportive bra. Sip on water to stay hydrated, and precede and end your workouts with a small protein-carbohydrate snack to provide quick and long-lasting energy and maintain muscle.

That's what Willard does.

"I'll have a natural peanut butter and jelly sandwich on whole-grain bread about an hour beforehand and a banana and whey protein shake afterward," she said. "I've also added 300 calories to my diet per day and have increased the frequency of my meals because I'm always hungry."

Emily Moore, RD, LDN, prenatal nutrition educator, said small frequent meals are a good remedy for morning sickness and heartburn, too. She advises women to eat six meals every two to three hours and consume fluids between meals, rather than during. It may also be helpful eat before getting out of bed.

"To avoid heartburn, don't lie down immediately after eating. Lay with your head slightly elevated, and avoid caffeine, chocolate and highly seasoned foods," Moore said. "Another common complaint, constipation, can be prevented by increasing high-fiber foods and fluid intake and engaging in moderate exercise."