Paula Fuhr was ecstatic after finishing her first triathlon. She swam 500 yards, biked 15 miles and ran 3.1 miles without having to walk, finishing the YWCA of Minneapolis Women's Triathlon in 1 hour, 38 minutes and 49 seconds, good for 245th out of 872. She was as fit as all of the other participants but had an extra challenge: She was 20 weeks pregnant.

"It was a perfect day; it was really a lot of fun," said Fuhr, 35, of Minneapolis. "My mentality was probably different being pregnant. I was just really happy to be doing it."

For years, women were encouraged to take it easy during pregnancy. Recent studies, however, show that Fuhr's exercise-while-pregnant approach can be good for women and their babies, and that most pregnant women are not getting enough exercise. A University of North Carolina study published in Preventive Medicine magazine found that 23 percent or fewer of pregnant women engaged in as much physical activity as recommended.

Dr. Mary Pukite Morrow, 40, an obstetrician/gynecologist who lives in Minneapolis, encourages her patients to be physically active and sometimes inspires them with her own experiences.

She trained slowly and steadily for the 2009 YWCA triathlon, when she was pregnant with her third child. She competed in August, finishing in 2 hours, 27 minutes and 22 seconds, and four months later gave birth to a healthy boy -- 7 pounds, 11 ounces.

While her experience was positive, she acknowledged that many pregnant women are cautious about exercising. "They're afraid too much exertion will have a negative effect," she said.

It has been a long-running controversy, with many people uncomfortable with the very possibility of a fetus getting jostled about during heavy exercise. For years, doctors were concerned that strenuous exercise could play a role in everything from miscarriage to too-few nutrients getting to the fetus.

But now the American College of Obstetricians and Gynecologists (ACOG) promotes exercise among women before, during and after pregnancy, saying that exercise can help reduce backaches, prevent or treat gestational diabetes and improve mood and energy. But it advises taking precautions, consulting with their doctor and avoiding certain sports, such as downhill skiing and contact sports.

Until 2002, ACOG recommended that pregnant women's heart rates stay below 140, considered a fairly low rate especially for a pregnant woman. Now, it advises women with uncomplicated pregnancies to get 30 minutes or more of moderate exercise on most days, and the Department of Health and Human Services tells women to aim for at least 150 minutes of moderate aerobic activity a week.

Another study, published in the Journal of Clinical Endocrinology & Metabolism, found that babies born to exercising women have healthier birth weights, lessening their risk of obesity later.

"If you get a fat mother who has a fat kid and becomes a fat adult ... the cycle of obesity continues," said Dr. Paul Hofman of the University of Auckland in New Zealand, co-author of that study. "We're looking for ways to intervene [in the obesity epidemic], and we wanted to see whether exercise during pregnancy would have an impact on fetal growth."

As fitness coordinator at the Midtown YWCA in Minneapolis, Ann Haugejorde advises pregnant women to make modifications as necessary (switch from a treadmill to elliptical, adjust the handlebars on a bike), and to use their rate of perceived exertion (instead of heart rate) to monitor intensity.

"It helps relieve stress, improves circulation, it promotes sleep. ... People come back afterwards and just thank you," said Haugejorde, who walked and swam through her own three pregnancies.

Sarah Longacre opened Blooma, a south Minneapolis studio focused on prenatal yoga, three years ago. A second Blooma opened this year on Grand Avenue in St. Paul.

"To most people, yoga feels really natural during pregnancy because they want to be relaxed and grounded," she said. "When they come to Blooma, there's a whole room of women who understand hemorrhoids and heartburn."

Competitive athletes face a different set of issues. For the past seven months, Olympic runner and former Duluth East track and cross-country star Kara Goucher has watched her belly swell.

"I expected I'd be able to train through the whole thing, to adjust to how my body was adjusting, that it wouldn't change that much," she says with a laugh. "It's been quite humbling."

Instead of running 80 miles a week, she lifts weights, jogs and cross-trains (Pilates, elliptical, biking and aqua jogging), and checks in with her doctor every two weeks.

"Reality caught up to me, and my body was like, you know, 'We need to shift down,'" she said. "I do feel like it's important to exercise during pregnancy ... but next time I'm pregnant I won't be too hard on myself. I won't feel like I need to get my afternoon run in no matter what; if my back is sore, I'll get in the pool or take a nap."

Sheila Mulrooney Eldred is a Twin Cities freelance writer.