It's often perceived as an exercise used to sculpt the trim types.

Mary Gordon, a certified Pilates instructor and nurse for 14 years, would like to change that image.

She has designed a Plus-Size Pilates class for what she calls the round-bodied woman because she believes fitness comes in all shapes, sizes and body types.

"It's not about size; it's about flexibility," Gordon, 62, said, adding that a 200- to 300-pound woman can roll back and forth in a Pilates exercise as easily as a small-bodied person can.

Her proof is in her pupils. At 256 pounds, 5-foot-2-inch Baleka Baker, 56, has more flexibility and core strength than many people half her weight. It is because she's taken the Plus-Size class with Gordon at Naturally Women, 6880 E. Broadway, for two years and loves it.

"I have a waist now," said Baker, a retired school librarian, who has dropped from a size 2X to a 1X, increased her hip and core strength so that she no longer walks with a waddle and had a more rapid recovery after carcinoma surgery last year due to her increased fitness level, she said.

Since the class was started at Naturally Women two years ago, it's grown from a few students in one location to about 50 students at six locations citywide.

The class offers women an effective Pilates mat workout with other round-bodied females, Gordon said, which eliminates intimidation and encourages support among participants. Hers is a rare find in Tucson, since most area gyms offer a one-size-fits-all group Pilates class.

"We don't have to feel self-conscious when we come here because we're all different shapes and sizes," Baker said.

Mat Pilates is a comprehensive form of exercise involving full range of motion, coordination, deep breathing, sustained mental focus and active contraction of all muscles in precise exercises done in a dancelike sequence, Gordon said.

Benefits include improved coordination, balance, blood circulation and strength for the entire body.

Lois O'Day, 65, who is in her ninth month of classes, said the most visible change she's seen is improved posture. "I can stand straighter now."

Pilates was developed between 1912 and 1926 by German boxer and gymnast Joseph Pilates. About 9.5 million people took Pilates in 2003, up from 2.4 million in 2001, according to the Sporting Goods Manufacturers Association's most recent statistics.

Gordon's one-hour class modifies traditional Pilates moves - such as The Hundred, Roll Up, Single Leg Curl, Rolling Like a Ball, Single and Double Leg Stretch, Spine Stretch, Saw, Side Kick and Seal - to suit challenges such as a bigger belly, large breasts, heavy arms and legs and expanded hips.

Gordon, an American Council on Exercise certified personal trainer and former tri-athlete, body builder and kickboxer, said the class evolved after she began working with Baker. She realized that while Baker, who had a personal trainer for seven years, was very strong, she lacked core strength. Core strength is the abdominal, hip and lower back area.

She may have found a niche in the growing plus-sized market. Now, 65 percent of Americans are overweight and obese, according to the Centers for Disease Control and Prevention.

Allyn Baker, 26, a massage therapist and Baker's daughter, recently took Gordon's Plus Size Pilates instructor training class. She feels there is a need for this type of class.

"Although the population is growing with regards to the number of round-bodied people, for some reason we as a society are not catering to that group. It's almost as if society looks at them and says, 'It's your fault that you got that way. Why aren't you trying to do something about it?' " Allyn Baker said.

Timothy Lohman, a physiology professor in the College of Medicine at the University of Arizona, has done research on long-term weight loss. He said that while research shows exercise alone has a small effect on body weight for most people, it results in better overall health.

"Even if they don't lose weight, research shows if they become more physically active, their risks for heart disease, cancer and diabetes decrease," he said.

IF YOU GO

What: Session of Plus-Size Pilates offered by certified Pilates instructor Mary M. Gordon.

When: 10 a.m. March 26

Where: Tucson Touch Therapies, 3903 E. Pima St.

Cost: Free

Details: Call 977-1004 for more information.

CLASS SCHEDULE

Plus-Size Pilates with Mary M. Gordon:

• Mondays, 3 to 4 p.m. at Naturally Women, 6880 E. Broadway, 722-3700. Membership required.
• Tuesdays, 2 to 3 p.m. Catalina Ladies, in the Catalina Highway area. Starts in April. Call 760-4197 for information.
• Wednesdays, 6 to 7 p.m. Tucson Touch Therapies, 3903 E. Pima St., 977-1004.
• Thursdays, 2 to 3 p.m. Offered by the Catalina Ladies. Starts in April. Call 760-4197.
• Also on Thursdays, 6:30-7:30 p.m. Physician's Institute of Exercise Physiology, 4570 N. First Ave., Suite 150. Call 977-1004.
• Saturday, 8:30 to 9:30 a.m., Fit To Be Tried, 4748 E. Grant Road, 881-1182. Starting in April.
• Cost: $10 to $15 a person per session. Introductory offer is buy seven and get one free.