Dr. John Ratey has studied the brain for more than 40 years.

As a psychiatrist, he has always been interested in how we can make our brains function better. And while he appreciates the magic of modern medicine, he has found that lifestyle factors have the most profound effects on the brain.

In particular, he has found that exercise is the number one thing we can do for brain health.

I had the opportunity to sit down with Dr. Ratey last week at his office in Cambridge, Massachusetts, to learn more about the effects of exercise on the brain, and what we can all do in our own lives to reap the benefits.

Dr. Ratey grew up as a competitive junior tennis player in Pennsylvania and competed in the US Nationals, so he was exposed to the power of sports and exercise from an early age.

And he was always fascinated by the brain, earning his first job out of college at Harvard’s Massachusetts Mental Health Center (MMHC).

But it wasn’t until attending the University of Pittsburgh Medical School in the ’70s that he really began to understand the causal link between exercise and brain health.

During that time, he learned about a hospital in Norway that was offering depressed patients to take either antidepressants or participate in an exercise program three times a day. Remarkably, both groups got better at the same rate.

That really piqued Dr. Ratey’s interest and he started to more closely follow exercise in the medical literature. His focus turned to Attention Deficit Disorder (ADD) when he learned about a Boston Marathon runner who developed symptoms of ADD after a knee injury forced him to stop running. The runner went to see Dr. Ratey and was put on ADD medication. However, after his knee was rehabbed and he was back training again, it was determined the medication was no longer necessary. That was back in 1982.

Since that time, Dr. Ratey has established himself as one of the world’s foremost authorities on the brain-fitness connection. He has written numerous bestselling books, including the groundbreaking ADD-ADHD Driven to Distraction series, Spark: The Revolutionary New Science of Exercise and the Brain, and Go Wild. He is currently a clinical associate professor of Psychiatry at Harvard Medical School.

Today, people have become much more aware of the effects of exercise on the brain.

Dr. Ratey said public interest in this topic really took off in the mid ’90s and it’s never stopped.

“Today we just know so much more about what exercise does,” Dr. Ratey told me. “It is simply incredible how powerful it is for the brain. Forget about its effect on blood pressure, sugar loads, weight, buffing you up, all that. That’s a given. But the effect on your brain is amazing.”

The health and wellness boom over the last decade, and related media coverage, has exploded our awareness of what exercise can do to improve mood, anxiety, stress, learning, creativity, and motivation. Dr. Ratey said exercise is also the number one weapon to prevent against brain erosion (including dementia and Alzheimer’s Disease), cancer, and inflammatory disorders.

Most people already know about the benefits of exercise by now, so I wanted to ask Dr. Ratey to prescribe the perfect type of exercise for the brain.

“The best exercise is something that you enjoy, with someone, done outside, in nature, and something that you’ll come back to,” he told me.

He said the ideal exercise is something that will get your heart rate up and force you to use your brain. You have to pay attention when you’re outside, which is why a trail run is much better than running on the treadmill, for example (Dr. Ratey has the trail running injuries to prove the concentration required).

But I was a bit surprised when he went on to discuss the ultimate exercise for the brain.

“I always tell people, the best exercise probably that you can do is dance,” said Dr. Ratey.

He did qualify that he meant vigorous dance that gets your heart rate up, not just flailing around. The reason dance is so powerful for the brain is because you have to practice and mentally focus on the right movements. Additionally, you have to follow music, and often stay in rhythm with a partner or group. All of that puts an incredible demand on your brain.

“The more demand on the brain—it’s just like the more demand on your muscles—the more you’re going to build,” said Dr. Ratey.

Image: Statista

In terms of cardiovascular exercise, Dr. Ratey is a huge fan of high-intensity interval training. “The more demand on your cardiovascular system, the better it’s going to be,” he said.

He also highly recommends squash. “That’s an incredible game,” he said. “High-intensity, probably the best aerobic workout I can think of.”

So does Dr. Ratey follow his own advice?

Best practices are fine, but I wanted to know what he actually does in his own life.

"My routine has always been to stay very active," he said.

Dr. Ratey has always had a habit of exercising in the morning. He has found the cognitive and emotional benefits of morning exercise stick with him long after the workout has finished.

He was an avid squash player for 30 years until a shoulder injury caused him to stop most racket sports. But even when he was a serious squash player, variety was always paramount.

In those early days, he would supplement his squash by going to the gym in the morning for weight training and a treadmill or elliptical workout. He was even one of the earliest adopters of the StairMaster, keeping one in his house (“We were animals on it!” he told me).

These days he does a lot of walking and running. On the day of our conversation, Dr. Ratey had gone for a morning run around the Charles River in Cambridge, and he was signed up to run a 5K over the weekend.

He also has a personal trainer come to his house twice a week for weight training. Although Dr. Ratey still does most of the exercises on his own, the trainer helps prevent injuries.

Dr. Ratey also spends a lot of time in Los Angeles with his wife, and they routinely start their west coast days with a morning 1.5 hour hike.

He and his wife have always been serious exercisers. Even their vacations are chock full of physical activity.

“Our ideal vacation is a place we go to called Rancho La Puerta, where you get up at 6am with a group of people,” he said, telling me the full group can be as large as 150 people. “And we climb a mountain for 2 or 3 hours in the desert in Mexico. And come down. And then every hour on the hour during the day there is another exercise activity you can participate in—yoga, tai chi, dance, spinning, the gym, circuit training.”

That’s Dr. Ratey’s perfect vacation. So you get the idea about the role exercise plays in his life.

Putting it all together, I wanted to see what recommendations Dr. Ratey has for all of us to preserve our brains as we age.

“The secret of brain health in general is knocking down inflammation,” he said.

There are a number of ways to decrease inflammation, but he says exercise tops the list. “It’s the number one recommendation for cancer treatment,” he said. “Number one is exercise. After obviously treating the cancer. But why? Because it boosts the immune system so greatly.”

After that, you have diet. Dr. Ratey says diet is probably as important as exercise, especially as we learn more about the microbiome and what food does to our body and our brains.

“I recommend to my patients and to everyone, limit your carb intake,” he said. “Especially processed food, which has mainly carbs in it.” He also advises to keep sugar levels in check, and to get sufficient protein and vitamins from your food (not from a pill).

One diet trend Dr. Ratey believes could have a beneficial impact is a daily fast—not eating from dinner the night before until lunch the next day. Most people say you can’t miss breakfast, but “Yes, you can,” says Dr. Ratey. “Because fasting is a way of stressing the body and stressing the brain in a very non-toxic way. And when you stress the body and the brain, you build it.”

Finally, Dr. Ratey stresses the importance of social connection for brain health. He said our addiction to electronic devices is stealing from our face-to-face human interaction with other people (not to mention, causing sleep deprivation which has negative health effects—Dr. Ratey doesn’t allow any screens in his bedroom). The addictive nature of screens is arguably the biggest problem in today’s world, according to Dr. Ratey. But exercise can be a very powerful antidote—especially exercise that fosters social bonding.

That’s why he is a huge proponent of joining a club or group exercise classes. He cited the amazing social networks (real, human social networks) that are built at fitness groups like Orangetheory and CrossFit. He said clubs like that bring together a wide mix of people who form genuine friendships around the common goal of improving their exercise. “A big part of the magic there is how the connection makes everything better,” said Dr. Ratey.

Exercise. Diet. Social connection.

With the major boxes checked, I asked Dr. Ratey if he had any final tips for brain health and longevity.

That’s when he was reminded of how a spry 92-year-old once answered that question:

“Sex!”

Of course, it probably helps to have a good sense of humor in the long run as well.