Kyu Lee has the bones of a young man, a surgeon told him a few years ago.

As a child growing up in impoverished southern Korea, Lee was fed rice gruel. The watery soup was bad for his teeth, which fell out over the years. When an oral surgeon replaced part of Lee's upper jaw with a bit of bone from his hip several years ago, the doctor was astonished.

"He said, 'I've never seen such healthy bone!' " Lee, 81, related recently, sitting on a wooden bench at Gold's Gym in Ashburn.

Lee told the story proudly, one of the benefits, he said, of a vigorous exercise regimen.

At least five days a week, Lee and his wife, Rhea, 77, visit the gym, where she does floor exercises, lifts weights and runs on the treadmill. He lifts weights, moving through at least 20 machines to exercise each muscle -- first biceps, then calves, a rowing machine for his back. And so on. Even before their excursion to the gym, the two walk 1 1/2 to two miles each morning in their Ashburn neighborhood.

They were among the first to join the gym when it opened seven months ago in an office complex off Route 7. Before that, they worked out daily at a gym in Sterling and before that in Tysons Corner. They have included exercise in their daily routine since Kyu Lee retired from his job as a microbiologist at Cornell University and the couple moved to Virginia to be closer to their two sons.

"Longer life is not really my goal," Kyu Lee said. "The improvement of the quality of my life is my goal. I feel more in control of my life."

The gym's staff members say that other gym users would never guess the Lees' ages from their upright posture and vigorous workouts. They called the two models for others, especially as holiday indulgers flood area gyms looking to shed winter pounds.

"I'm inspired to tell my own folks about them," said Tommy Kouchis, the gym's general manager. "If they can do exercise, anybody can do it."

The Lees, who have been married 57 years, tick off the benefits of their exercise. In the mid-1980s, Rhea suffered a herniated disk. On her physician's advice, she swam every day for six years to aid her recovery. She has been healthy ever since. Low blood pressure, low cholesterol, strong bones, all of which she attributes to exercise.

Kyu said that because of exercise, they are likely to live independently much longer and avoid becoming a burden to their sons. He said he is convinced that the exercise improves the couple's mental acuity.

"Healthy body, healthy mind," Rhea interjected.

Then there's the height issue. Research shows that the elderly really do shrink with age, because of osteoporosis, Kyu Lee said. But with exercise, he said, the cartilage in the spine is strengthened, and height loss is avoided.

"I began to realize that I was taller than my friends," Kyu said with a laugh. He imitated many of his friends' gaits, hunched over and shuffling, and contrasted it with his own ramrod straight walk.

The Lees' son, Philip, a technology consultant working with the government, said the discipline with which the couple approaches their health has been a constant in their lives. The couple moved their family to the United States in 1963 when they were in their forties.

"When they came here after passing 40 years old, in a life, that is over the hill, so to speak," Philip Lee said. "They virtually threw everything away, and they started here almost fresh."

The move came after nine years of separation during which Kyu studied at Cornell and Rhea remained behind with Philip. During the first part of their separation, when the Korean War raged from 1950 to 1953, they had no contact until an American soldier agreed to share his Army address with Rhea so she could mail letters to New York.

Kyu returned to Korea in 1958 and reunited with his wife and 12-year-old Philip, whom he had not seen since Philip was 3. Rhea soon gave birth to a second son. When Kyu was hired by Cornell in 1963, the family moved to the United States together, spurred, Philip said, by educational opportunities that America would afford their sons.

"I still recall how much trouble my mother went through to learn how to drive or even to pick up the phone," Philip said. "They sacrificed in a sense to provide their offspring the best opportunity to excel themselves."

In Korea, Philip said, his mother had to care for older relatives who were bedridden. The exercise is her way of avoiding the same experience.

"They've been doing that a long time," he said. "I feel like they're healthier I am."

Kyu Lee, 81, and his wife, Rhea, 77, work out at the new Gold's Gym in Ashburn at least five days a week.