If you live, you're going to get old. You can't stop it. But I'm doing something to celebrate life in the second half. It's not something we are good at. – David Glover

On a recent winter morning, sunlight spills over the paintings, books and mementos that fill Shirley Joel's New York apartment, where she sits editing video on her iMac computer. There's nothing remarkable about this scene — tens of thousands of people use Apple's Final Cut Pro software every day in America — except for one thing: Joel is 84 years old.

At an age when some of her peers adamantly resist the march of technology, Joel taught herself to use the software program so she could edit digital video.

Every week she produces and edits a television show about active aging for a neighborhood station, and that's what keeps Joel seated before the iMac for many hours each week.

"I don't have it 100 percent mastered, but I'm pretty good," she said. "My grandson is amazed."

Immersing herself in challenging projects ensures that Joel continues to exercise her brain, muscles and social skills during a life stage that sees many senior adults grow lonely and slip into mental and physical decline.

To those over 65, the mantra "Use it or lose it," applies, according to numerous studies. Gradual decline in overall health and cognitive function is inevitable with advancing age. However, seniors who challenge their brains, keep moving and maintain social connections reap benefits that go far beyond the enjoyment that comes from their active lifestyles

"We know that people who do these things tend to not experience rapid and severe declines in cognition as a general finding," said Kristi Williams, a professor of gerontological nursing at the University of Iowa.

Williams is co-author of a 2011 study that found cognitive and physical activity, social engagement and good nutrition had positive effects in maintaining memory and thinking ability for aging populations. The report concluded that medical guidance for older adults should be expanded to focus on preserving mental acuity as well as physical health and that senior adults should be encouraged to participate in activities that challenge their minds and keep them interacting with other people.

Embrace challenge

A born go-getter, Joel hasn't needed such counsel. Besides rearing three children with her husband, she pursued a career in advertising and retailing that included a stint as ad manager for Saks Fifth Avenue. Late in her career, she had to make the crossover from manual to computerized layout and design, as her whole industry did.

"I went enthusiastically," she said, with a zest that begins to seem typical as she talks about her television show, “Active Aging.”

“Our goal is to counter the image of aging and portray a vibrant approach to all aspects of living, whether you are retired or not,” Joel said about her show, which airs on the Manhattan Neighborhood Network, a public access television station. “We show older people embracing new challenges and participating dynamically in all aspects of society.”

Joel's husband, one of the original photographers for "Life" magazine, died six years ago, and she lives alone in Midtown Manhattan. She's determined never to stop learning — the latest iteration of that is her new goal to learn the Spanish language. Attending live theater is another passion for Joel, but the television show is the one that really stretches her.

“Telling a story is extremely creative,” Joel says of her volunteer job. “I interview the person, then develop a narrative around that person. It’s very challenging and extraordinarily interesting. Editing at the computer is labor-intensive and requires a lot of patience. I will sometimes say to myself, ‘What am I doing, spending hours at the computer?’ ”

Producing her show keeps Joel out in her community. She likes living in a city that has good public transportation and recommends it. Walking to and from the subway as she goes about her activities is good exercise, a key factor in maintaining cognitive function in senior adults.

Keep moving

As the demographic profile of the United States continues to go gray, optimizing life during retirement years will become increasingly important. The oldest members of the American "baby boomer" generation, born between 1946 and 1964, will turn 67 in 2013. That means the coming two decades will see the ranks of U.S. senior citizendom swell dramatically as more and more boomers turn 65.

Those aging boomers would do well to stay active. A 2011 Japanese study showed that mice that exercise daily had higher levels of glycogen — “brain fuel” — in their brains’ cortex and hippocampus, the areas responsible for learning and forming memories.

It appears those results are not permanent, however. Like muscle growth, the brain benefits of exercise disappear if exercise is discontinued, according to another study that compared the mice who exercised regularly, then stopped, with sedentary mice.

The 2012 study at Brazil’s University of Sao Paolo found that after the first week of inactivity, the previously active mice were much faster than the sedentary mice at remembering locations in a maze and had twice as many newborn neurons in their brains. After six weeks of inactivity, though, the mice that previously exercised showed about the same memory ability and neuron profile as the sedentary mice. The cognitive gains from exercise had been lost.

Williams advises that senior adults continue physical activities to the degree their health will allow, suggesting walking and swimming. Continuing scholarly work and reading will stimulate cognition, and staying involved socially with family, friends and community is important to optimal aging, she said.

Attitude counts

Sixty-seven-year-old David Glover feared aging, fought it, and finally embraced the wonder of living a long life. Glover, a career musician from Oakland, Calif., wrote a 90-minute one-man show about graceful aging, "Old Happens," which he performs from memory at senior facilities, churches and theaters. After performances, audience members stay behind to thank him for helping them see aging in a new light, and to share their stories.

"If you live, you're going to get old," Glover said. "You can't stop it. But I'm doing something to celebrate life in the second half. It's not something we are good at.

For Glover, things got better when he decided to accept the aging process instead of railing against it.

“I think God put us here to age and grow old, and I thank God I’m getting old,” he said. “Young was fun, but I’m old now. Let me enjoy my old years, just like I did the young years.”

Glover enjoyed theater throughout his life, but didn’t find time to indulge his interest until he got older. His positive attitude toward aging, and his ability to “play” at something he always wanted to do might reap hidden rewards.

A 2006 study in the American Journal of Psychiatry showed that the ability to “play” — enjoy family, hobbies and community activities — outweighs financial security and good health as a predictor of satisfaction during retirement for men. And a 2004 study at the University of Texas found that people with a positive attitude showed fewer signs of frailty as they aged than pessimistic people did.

Glover believes the baby boom generation will tackle senior adulthood with gusto.

"These are people who came out of a radical background," he said. "They've been fighters through the ’60s, and they are going to be more relentless."

Among all those feisty boomers are millions of people who will live longer — though not necessarily healthier — than previous generations of Americans did. U.S. life expectancy was 78.5 years in 2009, according to the United Health Foundation's 2012 America's Health Rankings. That's 1.7 years above the level in 2000. The extra years come at a price.

"Because Americans are living longer, we're seeing more problems with cognitive changes in advanced age," Williams said. "After age 85, almost one in two people have some kind of cognitive decline issue."

So why not take steps to avoid those declines by taking a word of advice from Shirley Joel?

“You find a passion,” she said, “maybe one you haven’t been able to develop. You tap different resources maybe you weren’t aware of. One really has to be willing to adventure, be flexible and try new things.”

Joel said she has never forgotten words uttered by one of her interview subjects, a woman who retired from life as a reporter for NBC, then joined the Peace Corps at age 63:

“Retiring? You retire a boat. You retire a debt. You don’t retire a person.”