I'm an 83-year-old doctor who still works 50-hour weeks. I never give any thought to retirement — I still have things to contribute.

• Dr. Joseph Maroon is a neurosurgeon, professor, and triathlete.
• He stepped back from performing surgeries five years ago, but still works up to 50 hours a week.
• He said work keeps him engaged and allows him to use his brain.

This as-told-to essay is based on a transcribed conversation with Dr. Joseph Maroon, an 83-year-old neurosurgeon living in Pittsburgh, about his decision to keep working at his age instead of retiring. The following has been edited for length and clarity.

At 83, I'm having more fun now doing what I do than I have in the past.

My career began in 1972 when I joined the neurosurgery department at the University of Pittsburgh after I'd finished my residency training. I've worked in the neurosurgical field for 51 years.

For decades, my day job was diagnosing and treating patients with major problems of the brain and spine, primarily through surgery. Five years ago, I decided to stop performing surgeries and focus instead on various research projects, and to increase my mentoring and teaching of residents and medical students.

I currently work around 40 to 50 hours a week, anywhere between six to 10 hours a day, on research, lecturing, and mentoring. I'm working just as much now as I was when I was doing surgery.

I'm not going to retire until I have to.

I still feel very relevant in my profession

I operated on patients until I was 77. I still feel I could operate, but think patients might question it at my age. Sometimes, in neurosurgery, the operations are very long, and I felt it was best not to push the limit, but I still see patients and consult.

I had a desire to devote more time to research. I'm currently working on a project involving surgical applications for augmented reality, among other things. As a surgeon, you can work with one person at a time. The work I'm doing now can potentially touch thousands of patients.

I'm a professor at the University of Pittsburgh, a consultant neurosurgeon to the Pittsburgh Steelers, the medical director of World Wrestling Entertainment, and a chairman of the National Science Advisory Committee of the Chuck Noll Foundation, which supports research into ways of diagnosing and treating brain injuries, primarily occurring in sports.

I've been welcomed in my department as a senior member. With 50 years of experience, I think there are still things I can contribute, such as research and giving suggestions to younger initiates as a mentor. I still feel very relevant in my profession.

I think my family is a bit surprised that I'm still working, but they're also pleased and encouraging of me.

There's currently a debate in the political realm around age

It's hard to generalize, but if the quality of an individual's life is such that mentally and physically, they're able to work later, I certainly encourage that. If you've had a stroke or have early dementia, these are factors that will enter into the equation of how long or how effectively you can work.

Currently, there's a debate around President Joe Biden regarding cognitive awareness. I think people are aware of his age and former president Trump's.

At age 70, I had to take a neuropsychological test as well as a physical examination to continue to operate. Air traffic controllers, pilots, and others also have to undergo similar testing. Is this a consideration for those working in politics? I'll leave that up to others to decide.

Everyone ages at a different rate depending on genetic and epigenetic factors, so there's no one age I believe is a limit. Some people in their 90s are as sharp as can be; others in their 60s have significant problems processing information.

In terms of when people should retire, I think it's a matter of assessing one's faculties in terms of mental and physical abilities with objective scrutiny. Do you still have your senses? Is your brain still functioning at a level that you feel it should at this point? I feel fairly comfortable with both of those.

I never give any thought to retirement.

Work and exercise keep me engaged and healthy

I was an athlete in college, but when I got into medicine, I focused almost entirely on my work.

In 1979, a cataclysmic "lifequake" occurred, and my father died of a heart attack aged 60. I had to quit neurosurgery. One day, I was doing brain surgery on patients with tumors, and the next week, I was working in a truck stop bequeathed to my mother by my father, filling up 18-wheelers and flipping hamburgers.

It was about a year before I went back to neurosurgery. I was very depressed, floundering, and barely functional.

During this time, I realized I was very "successful" in terms of authority and recognition, but I'd neglected other aspects of my life.

One day, a friend called me and said, "Joe, you need to go for a run." I said, "I'm 20 pounds overweight and very depressed," but I found a pair of shoes and went around the high school track four times. I was tired and out of breath, but something very strange happened that night. I slept for the first time in four months.

It was a tipping point for me. I subsequently started to cross-train. I got a bike and learned to swim. Then, I entered into a mini-triathlon. It became a lifestyle. I've probably done about 80 triathlons, including eight Ironman triathlons.

I decided my goal was to die "young" as late as possible.

I try to exercise for an hour to an hour and a half a day, five to six days a week.

The work that I'm doing, as well as exercising, is allowing me to use my brain, which develops neuroplasticity. In some ways, the brain is like a muscle; you need to "use it or lose it." Research and work keep me fully engaged. I'm interacting with others and am challenged.

I feel very fulfilled with what I'm doing now.