ROSLINDALE, Mass. — Free weights, treadmills, stairmasters, toning up and pumping iron. Personal trainers guiding athletes to better bodies and good health. Is this Jack La Lanne? Gold's Gym?

Not exactly.

On the ground floor of the Hebrew Rehabilitation Center for Aged in Roslindale, residents rebuild muscle tissue and self-esteem as they work with volunteers and staff in a weight-training program that is revolutionizing the way healthcare professionals see seniors — and how they see themselves.

There's not a rocking chair or glum face to be found at the center's Fit For Your Life headquarters, as the specialized strength-training program has come to be called. Approximately half the residents at the Hebrew rehab center pump iron. Is the program merely the outgrowth of a perverse and impossible forever-young culture, or is there meaning behind the madness? Just what is it?

"It's a Godsend, that's what it is," raves center resident Ben Engleman, 93. "When I arrived at the facility four years ago, I couldn't comb my hair." Engleman uses a walker and a wheelchair, and now works out three times a week on three different machines that exercise the arms and legs.

Fit For Your Life grew out of a small trial study conducted at the Center in 1990 by Dr. Maria Fiatarone of USDA's Human Nutrition Research Center on Aging at Tufts University, and a larger study with 100 participants conducted four years later. According to a 1994 report published in the New England Journal of Medicine, the two studies proved that in long-term care facilities, frail residents in their 80s and 90s actually become stronger and more mobile with high-intensity weight training.

Moreover, even those seniors who come to the program with profound muscle weakness can benefit from Fit For Your Life. Through exercise, Fiatarone argues, "disuse and undernutrition have the potential to be prevented or reversed."

Targeting muscles in the hips and knees, the regimen seeks to strengthen the body so that falls and functional disability do not occur. "Ultimately," says Jodie Portman, assistant director of corporate communications at the Center, "this type of intervention could be a key to reducing disability and its cost as people age, and may help delay entry into a long-term care facility altogether."

Irving Breitman, 90, has been transformed by the program. Legally blind and hearing impaired, the former lawyer from Newton has worked his way up from three to five or six machines, and lost 12-1/2 and-a-half pounds in three months.

Ed Rosenthal, the original poster-boy for the 1991 program who recruited both Engleman and Breitman, was "an easy sell," according to Evelyn O'Neill, a fitness specialist on the original study and current coordinator of Fit For Your Life. When he came to the Center nine years ago, the former biology teacher thought, "A nursing home: rocking chairs, reading, this can't be me."

Rosenthal, 92, still works out three mornings a week for 30 minutes, and says that everyone in his family has been inspired to take up exercise, too.

O'Neill, who travels internationally and works locally to promote fitness programs in other long-term care facilities and nursing homes, believes that "exercise is a preserver," and that it "enhances the quality of life" for the Center's 725 residents, at least half of whom participate in some kind of weight-training.

"It's physically as well as psychologically good for them," explains O'Neill. Depression is a root problem for the elderly, she says, and exercise creates a "whole good feeling" that can "alleviate many [physical] symptoms."

Rose Karsh, a 100-year-old resident who testified before Congress in 1992 to promote the funding of exercise research for the elderly, still comes to the program. "She dies for the contact and camaraderie," says O'Neill. Most participants, indeed, never miss a class.

Elaine Barron, 68, agrees. "I don't want to lie around feeling sorry for myself," she says. And she doesn't. Three times a week she attends the program, despite her rheumatoid arthritis.

For those unable to make the trip down to the Center "gym," portable free weights are brought to them.

What are the coordinator's hopes for the future? O'Neill would like to bring Fit For Your Life's lessons to other locations as well. Even more importantly, she would like to promote fitness training in the general public so that people "could avoid com

ing here."