Joan Virginia Allen of Ojai, Calif., practiced elder law before switching jobs at age 60 — and deciding to try to work another 60 years. “I wanted to challenge what society says about getting old,” she said. Now, at 82, she’s a fully booked life coach. She’s also part of a trend. People age 75 and over, including our fresh-on-the-job president, are the fastest-growing group in the labor force, even though “age discrimination is very real,” said Susan Weinstock, vice president of financial resilience at AARP.

I interviewed eight older workers about the wellness habits that have helped them achieve career longevity and found several commonalities that are backed by research. Over the decades, these workers have embraced healthy living in terms of diet, exercise and mindfulness. They have also relished challenges, maintained a sense of purpose and continued to learn from job experiences. All of these habits have positioned them to add value at work by sharing wisdom gained over their long careers with younger colleagues. It’s a virtuous circle; their approach to work and living leads to their job success, and their job success reinforces their approach to work and life.

Not all older employees, of course, are happy about having to work beyond a certain age. Many are facing financial pressures and have delayed retirement for the paychecks, not necessarily the thrill of their jobs. Richard Besdine, an 80-year-old professor of medicine at Brown University, said those compelled to work may see fewer wellness benefits from staying active through employment. Those who can’t control their schedules are especially vulnerable to health issues.

Although this article is geared toward older people who are eager to continue working, some of these strategies may help reluctant older employees, too. Here is what I learned from my interviewees.

They see business as pleasure

When he was 71, Eric Kandel won the Nobel Prize for discovering the role of neurons in storing memories. Had personal achievement been his priority, he might have retired, with no higher honors to chase. Instead, at 91, he still runs his lab at Columbia University’s Zuckerman Institute, supervising a team of researchers, some of them six decades his junior.

Staying busy wards off mental decline, but that’s not why Kandel is forging ahead in his field, writing prolifically to develop his research ideas. “I do these things because they give me great pleasure,” he said.

One reason work provides pleasure is because it requires meeting challenges. Kandel likes to “slug it out” in his lab, often grappling with unfamiliar concepts to inform his research. “You write about something and — boom — all of a sudden it becomes clear to you,” he said. 

Besdine also thrives on the demands of his field, “voraciously” reading medical literature and holding an early-morning journal club for colleagues to discuss important papers. Continuing to work “isn’t a health decision, it’s a pleasure decision,” he said. The personal benefits are “side effects. The fundamental driver has been that I want to know every strategy to keep old people vital, both physically and cognitively. And now I am one!” 

This attitude is protective. Older people who revel in challenges are more likely to do well on cognitive tasks, said Lisa Feldman Barrett, a psychology professor at Northeastern University and author of “Seven and a Half Lessons About the Brain.” Her brain scan studies suggest that unusually successful aging may be related to how tenacious a person is.

They exercise and eat healthfully

The older workers I spoke with rely on exercise for body and brain health. Kandel walks in the park near his home. Besdine is a “squash lunatic,” skipping lunch to conquer co-workers in their 20s.

Most of my interviewees eat Mediterranean diets rich in omega-3s. Half of them reported being vegans or vegetarians. Some are avid gardeners who enjoy their own fresh produce.

They take few or no supplements, but some do consume one item that might have anti-aging properties: coffee. Donald Weaver, a neurologist and chemist at the Krembil Brain Institute in Toronto, found that roasted coffee beans release compounds that may break up proteins linked to Alzheimer’s.

He’s not overselling the benefits: “Who knows, but it sure won’t hurt.” He said similar research is being conducted into the potential advantages of maple syrup; curcumin, a component of turmeric; and fruits and vegetables.

They manage their stress

All of my interviewees cited their ability to relax as key to avoiding burnout. Besdine does so by reading fiction out loud to his wife, a 73-year-old aging specialist at Brown, in front of their fireplace. Musette Henley, a 79-year-old working in customer relations for the U.S. Postal Service in Chicago, has recharged for many years by walking to Lake Michigan and meditating while watching the water.

Another example is Sybil Jordan Hampton of Arkansas, who retired as president of a philanthropic foundation at age 61 and started a consulting practice catering to nonprofits. Now 76, Hampton is still consulting — and still relying on what she called “the wonderful life lessons that my parents, grandfather and community gave us for living well in trying circumstances.”

In 1959, when she was part of the second class of Black students to integrate Little Rock Central High School, her parents gave her two pieces of advice: work hard, and listen to classical music. So, for 60 years, she has spent time relaxing to classical music at night. She also starts many mornings by reading the hopeful prayers of enslaved people in the antebellum era. “I am extraordinarily upbeat with tremendous faith in the face of darkness,” she said.

Music and other forms of de-stressing promote long-term cognition and boost memory and creativity. They also improve sleep, which is especially important for older people. Sleeping soundly and following wakefulness patterns help the brain efficiently maintain the body’s energy balance, a process known as allostasis, said Barrett, the Northeastern professor. “If you don’t replenish energy spent, you pay a little metabolic tax, and [those taxes] may add up faster for an older person.”

They find meaning as 'wisdom workers'

Historically, elders found utility in nurturing their grandkids. Today, with families more geographically dispersed, “there’s less opportunity in your backyard,” said Chip Conley, founder of the Modern Elder Academy, which helps mostly middle-aged workers — but a number of older people, too — reinvent their careers, often to influence younger generations. Many seniors still find meaning and community in retirement, but others find it by prolonging their careers.

Kandel, the Nobel Prize winner, continues working partly for the enjoyment of supporting early-career scientists. “I’ve been doing my job for 60 years, and they’ve been doing it for two or three,” he said. “But some are better than I was at their stage. I encourage them along those lines.”

And Hampton now offers her consulting services to young people starting nonprofits that seek to improve equity. “Everything I’ve done has aligned with my passions,” she said. 

Opportunities for giving back are growing as companies recognize the particular skill sets of older people, whom Conley refers to as “wisdom workers.” Not all cognitive abilities fade as we get older; some skills, such as pattern recognition, emotional intelligence and teaching, can keep improving until very late in life, said Dilip Jeste, a neuropsychiatrist at the University of California at San Diego and author of the recent book “Wiser.”

“Employers love the soft skills older people bring to the workforce,” said Weinstock, the AARP vice president.

Sometimes, employees move to other positions in the same organization to become wisdom workers. Last year, for example, Besdine, the Brown professor, stepped down from managing people to concentrate on his true loves: teaching and mentoring.

Or senior employees might become wisdom workers in encore careers. When John Reagor of Bedford, Tex., became bored after retiring from the Postal Service — following 25 years in the Navy — he “un-retired.” At 73, he’s excelling in a role training employees at a large retail store, thanks to his improved emotional control — a facet of wisdom. He has always loved interacting with co-workers, but when challenges arise, he’s better now at managing relationships with others and his own feelings. “Find what it takes to get control,” he said, “and do that.”

Another important aspect of wisdom is self-knowledge, Jeste noted. After her legal career and a stint as a dynamic movement coach, Allen realized she wanted to become a life coach in her 80s. “I never intended to do it, but it tickles me that I started a business at 81, and by 82, it was successful.”

“Just be open to new ideas,” she recommended. That’s the other distinctive quality that Conley sees among active older people wanting to give back: curiosity. Wisdom workers are “first-class noticers,” he said. “You move from trying to be interesting to being interested.”

Matt Fuchs lives in Silver Spring, Md., and writes about health and culture. Follow him on Twitter.