Fit to Be Moms : Exercise: Gym at hospital helps pregnant women work out safely.

When Debby Harrisberger got pregnant, she decided she didn’t want to “sit around and get fat.” She bought an exer cise video but couldn’t muster the motivation to work out alone in her living room. She was reluctant to join a health club, fearful the instructors wouldn’t know what type of exercise is safe during pregnancy.

Besides, she said, “I didn’t want to be around all those skinny minnies.”

Now five months pregnant, Harrisberger, 27, has found a place to work out: the PregnaGym at Humana Hospital in West Hills. The gym, which opened in June, offers stationary bicycles, a full line of Nautilus equipment designed for pregnant women, and low-impact aerobics classes that follow the guidelines of the American College of Obstetrics and Gynecology.

Staffed by registered nurses, the gym is intended to help women have a more active and comfortable pregnancy by reducing pain in the back, abdomen, legs, hips, neck and shoulders.

“I feel really comfortable here,” says Harrisberger, who lives in Canoga Park. “I haven’t asked a question yet that they couldn’t answer.”

The Humana gym, one of 20 franchised nationwide, is the only PregnaGym in Los Angeles County. It was designed by Douglas Hall, a gregarious obstetrician from Ocala, Fla., who was inspired by his wife’s miserable first pregnancy.

The next time around, Hall put his wife on a weight-training and cardiovascular exercise program to stretch and strengthen the muscles causing her discomfort. Her pregnancy and delivery went so smoothly, Hall says, that he built a gym onto his office and developed an exercise program for his patients.

“This is an athletic event worse than any marathon,” Hall says. “It only makes sense to get ready for it.”

Women can use the PregnaGym throughout pregnancy and for three months after they deliver. Membership costs $25 a month for women scheduled to deliver at Humana in West Hills. The cost varies for those planning to deliver elsewhere.

Research hasn’t proved that exercise during pregnancy makes labor less painful. However, in a 1987 study of 845 women, published in the American Journal of Obstetrics and Gynecology, Hall found that patients who completed a PregnaGym routine more than 64 times during pregnancy had fewer Cesarean sections, less need for pain medication during labor, a faster recovery and a better self-image than patients who exercised less frequently or not at all.

“Instead of going into labor petrified, they say, ‘I’m going to push this sucker out,’ ” Hall says. “The confidence makes so much difference.”

Leslie Robbins of Woodland Hills, three months pregnant with her third child, believes exercising at the PregnaGym will increase her stamina and boost her self-esteem.

“I want to like my body when I’m pregnant,” says Robbins, 35. “A lot of women have a stigma about that.”

Richelle Fina, seven months pregnant, says the gym has inspired her to continue exercising after she gives birth.

“My legs will be in better shape when I deliver than they were when I got pregnant,” says Fina, 25, who lives in Granada Hills.

The PregnaGym looks like a traditional gym, with Nautilus machines to exercise the major muscles, but some of the equipment has been modified. For instance, a traditional leg-curl machine is designed for a person to lie on her stomach, place her ankles under a padded roller and curl her legs upward--not exactly the ideal position during pregnancy. But with the PregnaGym leg curl machine, a woman can strengthen her hamstrings while lying on her side.

Similarly, the PregnaGym has no machines that require a woman to lie on her back. Lying in that position during pregnancy can compress the main vein leading from the lower body to the heart, cutting off the blood supply and causing nausea and sweating, says Linda Katz, a Humana obstetrician.

When a woman joins the PregnaGym, a registered nurse tests her flexibility and strength, reviews her medical history and physician’s recommendations, develops an appropriate program, then re-evaluates the routine every 10 weeks. A nurse also checks the patient’s blood pressure after each exercise session. The stationary bikes are set to beep if a woman’s heart rate exceeds 140 beats per minute.

Becky DeLeon, the facility’s nurse coordinator, says members enjoy the camaraderie in the gym, where they can swap stories about breast-feeding and morning sickness.

“Husbands--no matter how wonderful they are--can’t quite relate.”

Where and When

What: PregnaGym.

Where: 7325 Medical Center Drive, Suite 203, West Hills.

Price: $25 a month for women who deliver at Humana in West Hills; $50 for those who will deliver elsewhere.

Call: (818) 226-3656.