How a physician with a 1 a.m. bedtime optimizes his health: I try to 'tick all the longevity boxes that I can'

When most people are wrapping their workdays and commuting home, Dr. Ronald Primas is often on his way to meet with patients.

Primas’ in-office work hours usually end by 6 p.m., but as a New York City-based concierge doctor who makes house calls and has patients whose “work, travel, or medical situation makes a conventional appointment impossible,” he’s essentially available around the clock, he says. “I often go to bed around 1 a.m., or later when a patient needs me.”

His work involves a twist: More than three decades into his medical career, the internist-by-training considers himself a longevity physician. He tests patients to assess their genetic health risks and develops personalized health plans for them based on the results, he says. He still conducts urgent-care appointments, but his focus — dating back to the 1990s, he says — is preventative care, trying to help people develop healthier daily routines to ward off future chronic diseases or aging-related declines.

“At that time, no one was using terms such as healthspan, biological age or longevity medicine,” says Primas, 66. “We did not have wearables, genomics or [artificial intelligence]. Yet the principle was already clear: The trajectory toward chronic disease often begins years before the first symptom, and preserving function matters as much as treating illness.”

Today, “the science, tools and public interest have caught up” to the idea behind longevity medicine, he notes. Physical and mental health are often associated with success, and generally healthy people report feeling more productive at work. The industry has become awash in buzzy biotech startups, funding from billionaires, expensive longevity memberships at medical clinics and gyms, and plenty of biohacking influencers on YouTube and TikTok.

Primas, for his part, is a believer in the power of small habits: “Little tweaks that you do every single day add up,” he says. And he tries to practice what he preaches. “I can tell my patients until I’m blue in the face about what to do. Unless I lead by example, they’re really not going to pay attention to it. I try [to] tick all the longevity boxes that I can.”

Here, Primas discusses how he structures his daily health routine, from his wearable devices to a diet rich in plant-based foods. Always consult with your primary care doctor before implementing any major changes that can affect your health.

Ronald Primas: I work out seven days a week. I do strength training three times a week, and I do high-intensity interval training. I do a Norwegian four-by-four [a type of interval training that targets heart health] twice a week, and 45 minutes of zone-two training [a form of exercise that focuses on raising your heart rate over time] twice a week. On weekends, I focus on stretching and balance training.

I protect exercise time as I would an important clinical appointment. I typically train in the evening after work. I also try to take a 20-minute walk after each meal — it’s a simple way to interrupt sedentary time and can help blunt the post-meal rise in blood sugar. I make a point of getting up and moving at least once an hour during the workday, often doing 10 to 20 bodyweight squats.

During unusually busy weeks, if I can’t complete my normal workout, I’ll still do a shorter session, walk, mobility work or a few sets of resistance exercise. Something is almost always better than nothing.

I optimize my sleep. I have a consistent bedtime. I don’t go to bed until like 1 a.m., maybe later than that, but I wake up around 9 a.m., so I’m in bed for eight hours and sleeping for about seven-plus hours a night. And it’s quality sleep. I make sure that my bedroom is completely dark. I make sure that it’s cold and it’s 67 degrees or below, and I have a comfortable bed.

CNBC Make It: How do you structure your diet?

Primas: I follow the way our pre-agricultural ancestors lived as much as possible. I guess you can call it a paleo diet. I eat only whole foods. No grains, no dairy, no added sugar.

I choose to get my fiber and calcium from root vegetables like parsnips, celery root, turnips and sweet potatoes. I eat a lot of tuna, salmon and grass-fed meat, and always complement it with vegetables and nuts. I eat fruits like blueberries, raspberries, and blackberries — a variety of whole fruits can be part of an excellent diet.

Our meals at home are intentionally simple and built around a reliable rotation of protein, vegetables, healthy fats and a few practical staples. Eating well does not require elaborate cooking every night, or expensive fish or meat. The most important pattern is one built around minimally processed foods, which can include [fresh or frozen] vegetables, beans and lentils if tolerated, eggs, plain yogurt, canned salmon or sardines, frozen berries, nuts and olive oil. The goal is not a perfect diet. It is a durable one.

I follow a time-restricted feeding window: I have two meals and a snack within a six-to-eight-hour range each day, and a hard stop for eating within four hours of bedtime. You get your highest-quality sleep when you don’t eat too close to bedtime. The longer before bedtime that I eat, the healthier that I am, the better my health metrics are on my Oura Ring and Biostrap [wearable health trackers].

CNBC Make It: What habits have you built specifically for your brain health?

Primas: No smoking. That’s, like, a given. The plant-based fats in my diet — avocados, walnuts, fish oil tablets, algae oil tablets — help support cell membranes throughout the body, including the brain. The fatty fish in my diet provides DHA (docosahexaenoic acid), an omega-3 fat especially concentrated in the brain and retina.

What really helps the brain is exercise, especially high-intensity interval training. Anything is better than nothing. It increases this hormone in the body called BDNF, brain-derived neurotrophic factor, which can stimulate the growth of neurons and increase neuroplasticity.

And then, of course, quality sleep, because your brain does self-cleaning while you’re sleeping. Chronically cutting it short has consequences for cognition, mood, metabolism and long-term health. Sleep is when the brain consolidates memory, recalibrates stress and immune signaling and supports other restorative processes.

For stress reduction, I do Qigong, which is a form of meditation, whenever I get a chance. There’s another thing that I do called HeartMath breathing. You clip this device on your ear and you sync your breathing with the technology.

Also, I’m very social. My wife and I have a lot of friends, and we hang out, do fun things together and take a lot of vacations. I try to protect time for my wife, family, friends and our dogs. The goal is not to create a perfect, hyper-optimized life. It is to create a routine that is repeatable.

CNBC Make It: Given the importance of social fitness for longevity, what are some lessons you learned over the years that make it easier for you to be social?

Primas: The main thing that I’ve learned over the years is not to sweat the small stuff. When I was younger, I used to pay attention to what people thought of me, and being judged, and all that stuff.

At this point, now that I’m older, I don’t care. But I wish I’d learned that when I was younger, and I try and pass that on my kids.

CNBC Make It: We’re nearing the end of our chat, but I can’t wrap without asking you the question that I always ask longevity experts. What are you reading these days?

Primas: Even though I do preventive medicine, I’m still a board-certified internist, so the majority of my reading happens to be journal articles.

I just bought Michael Fossel’s book, “Aging: How Aging Works, How We Reverse Aging, and Prospects for Curing Aging Diseases,” and Eric Topol’s book, “Super Agers: An Evidence-Based Approach to Longevity.” I haven’t gotten to those yet.

But I’m a nerd. Mostly, what I do is just stay up-to-date on medical literature.

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