PERSONAL HEALTH : Exercise Options for Pregnant Women

Physicians have long debated whether pregnant women should exercise--and if so, how much? Recent research suggests that moderate exercise can be safe and improve well-being, perhaps even eliminating the need for painkillers during labor.

Here’s a sampling of the findings.

* Water exercise during pregnancy is ideal, says Dr. Vern Katz, an associate professor of obstetrics and gynecology at the University of North Carolina, Chapel Hill.

“As pregnancy progresses, women feel more encumbered as their weight increases,” he says. “It is easier to get overheated. Exercising in water takes care of both the temperature and the balance problems.” He recommends either swimming or a structured water aerobics program.

* Step aerobics can be safe during pregnancy, according to a poll conducted by the Cooper Institute for Aerobics Research in Dallas. The survey was sparked by numerous inquiries from physicians and women about step classes, says Susan Johnson, director of continuing education for the institute.

“Most doctors said stepping can be done safely during pregnancy, with some caveats,” Johnson says. “Any kind of exercise during pregnancy, including stepping, should be done (in moderation). The goal is not to improve fitness (but to maintain it).

“If you have never stepped, begin with the lowest possible step height, the doctors polled said. Many of them advised women already in their third trimester not to start a new step program. Most recommended a step height no higher than 8 inches while pregnant.”

(Also: Look for classes with minimal turning and minimal choreography to reduce the chance of tripping or falling. And during the last trimester, use the lowest step height.)

* Exercising during labor might not sound appealing, but Dr. Raul Artal, USC professor of obstetrics and gynecology, says it can eliminate the need for pain medicine. In an ongoing study, he monitors women as they pedal a stationary exercise bicycle for 20 minutes during the early stages of labor. About 60% reported pain relief dramatic enough to eliminate the need for painkilling medicine. The exercise spurs production of the body’s natural painkillers, says Artal.

Pregnant women should not expect to improve fitness during pregnancythe objective, experts say, is just to maintain it. Nor should pregnant women try to reduce body fat; the aim is to avoid excess weight gain.

To help pregnant women and their doctors decide on the best activity regimen, the American College of Obstetricians and Gynecologists offers extensive guidelines for exercise:

* Maternal heart rate should not exceed 140 beats per minute.

* Strenuous activities should not be performed for more than 15 minutes at a time.

* No exercise should be done in the supine position after the fourth month of pregnancy.

“Pregnant women should continue a normal lifestyle,” says USC’s Artal. “If you were used to exercising before you got pregnant, you can probably continue to do so, realizing that certain changes in the exercise routine might be necessary.”

Women at risk of premature labor, and those who have placental problems, vaginal bleeding or other problems, he adds, might be better off doing isometric exercises (so-called “static” exercises to increase muscle strength by contracting and relaxing them).

“Pregnant exercisers should stick with low-impact activities,” the Cooper Institute’s Johnson says, “such as walking, stationary cycling--or outside cycling if you are good at it--swimming, or step aerobics.”

Joints are more susceptible to injury during pregnancy, due to hormonal influences that cause the connective tissues to become more lax and joints more unstable. For that reason, Johnson warns, avoid an overzealous warm-up and stretch period: “Overdoing it will contribute to the joint instability.”

Pregnant women might incorporate strength training--especially of the arms, back and shoulders--into their workout routines, Johnson says. The exercise will get them in shape for lifting and carrying the baby.

Individual exercise prescriptions, a wise idea for everyone, are vital during pregnancy, say experts. They advise continued medical supervision of an exercise program throughout pregnancy.

“Check with your doctor before exercising,” Johnson advises. “Every pregnancy is different. Even a marathon runner could develop high blood pressure or diabetes.”

The second trimester might be the most comfortable one for exercising regularly, Johnson suggests. During the first trimester, many women suffer fatigue, she says; during the last trimester, increased weight can make movement uncomfortable.