Edgar and Selma Davis work out at several gymnasiums: the Acme in the Bala Cynwyd Shopping Center; the ShopRite in Parkside; the Pathmark on Monument Road near City Avenue; and the Super Fresh on Lancaster Avenue in Wynnewood.

Yes, the Davises get their exercise while food shopping. Four or five days a week, they visit one of their favorite supermarkets, and while Selma, 75, searches for grocery items, Edgar, 87, pushes around a cart, sometimes succumbing to an impulse buy but mostly enjoying the cornucopia. They estimate their shopping expeditions keep them walking 20 minutes to a half hour.

"In supermarkets, you don't have to worry about uneven pavements or curbs," says Selma, "and the temperature is always comfortable."

Here is another example of functional fitness. The shopping trips get them out of the house, stimulate their senses, put them in the company of people, and, most important, get their bodies moving. This enables them to function better. At the same time, they are performing a function, accomplishing the task of acquiring food and filling the pantry.

"For a long time, our children thought we were nuts," Selma confides. "But you have to shop anyway, so you might as well take advantage of it."

Edgar and Selma became regular walkers after a 1990 trip to Hawaii, one of more than 30 visits they have made to those enchanted islands over the years. While there, they walked every day, at a leisurely pace, from Waikiki to Diamond Head, around the famous crater there, and back, a round-trip of 12 miles, they estimate. The experience was so exhilarating they decided they would continue daily walks when they returned home.

So they began walking around their Bala Cynwyd neighborhood. Then, they began hoofing it to the Acme on food errands. At the supermarket, the conditions were so pleasant they made the jaunts part of their exercise routine. For a while, twice a week, they drove to Atlantic City, where they walked from the Showboat casino to the Ventnor pier and back.

Edgar grew up in Oak Lane and attended Central High School. Selma grew up in Bala Cynwyd and attended Lower Merion. Both went to the University of Pennsylvania and both will tell you, unabashedly, that they were and are nonathletic. No tennis or softball, no 5Ks or mini-triathlons. Edgar allows that he did swim a bit in college, but mainly because he didn't want to be a sofa spud.

To supplement their walking, Edgar practices stair-climbing by walking up and down a few steps repeatedly. He also rides a stationary recumbent bike for about 15 minutes and lifts four-pound dumbbells, 10 to 15 reps, lowering the weight slowly during the negative phase. Selma walks on a nonmotorized treadmill for about 20 minutes, pedals a recumbent bike for 15 minutes, and lifts light dumbbells as well.

Next Sunday, the enthusiastic couple will celebrate their 52d wedding anniversary. Edgar was a confirmed bachelor until age 35. Then he was introduced to Selma, and something happened.

"Damned if I know," he says, chuckling. "My mother pushed me and wanted to get rid of me, I guess, and they all liked Selma."

"His mother loved me," Selma corrects.

For 38 years, Edgar worked for PGW marketing gas to new construction. After retiring in 1989, he began a second career as a photojournalist. The person whose work his photographs most often adorned was his wife, who went from composing summaries of scholarly articles to writing travel stories and profiles for local newspapers, as well as four crime novels.

Among the prominent people she has interviewed are Lower Merion grads Alexander Haig and James Billington (Librarian of Congress) as well as actor Robert Wagner, football stars Tom Brookshier and Tommy McDonald, and the Tuskegee Airmen.

Today, the Davises are healthy and vibrant, but, as Edgar observes, "when you get to be 87, you don't get there without some problems." Edgar has had bouts with melanoma and prostate cancer. Selma has had to struggle with spinal stenosis. By taking long strides when she walks, she has been able to stretch her muscles and alleviate the pain.

"Never give up," she says. "Whatever you think you can do, do it!"

When she turned 65, Selma learned that her blood sugar, cholesterol, and blood pressure were high. Rather than take medication, she reformed her diet. Today, that means a breakfast of oatmeal sweetened with fruit, an egg-white omelet, and, throughout the day, no sugar, no salt, no fat, and nothing white (as in white flour, white bread).

Edgar doffs his blue cap to reveal a thatch of hair.

"Oh Vanity, thy name is Edgar," he quips.

"My mind is still sharp," he says with a merry smile. "I never thought I was the sharpest knife in the drawer, but I enjoy a good life and I'm pain-free."