In any given week, my productivity level tends to hinge on (more or less), the following factors—how well I’ve slept, how healthy I’ve eaten, and how much I’ve moved. When things are hectic, as life sometimes is, exercise is usually the first thing to go. On weeks this happens, my productivity takes a dip. I’m easily distracted, I can’t seem to stay still for long, and it takes me much longer to fall asleep. I’m also grumpier. Let’s just say that I’m not a very fun person to be around when I’ve been sedentary for long periods of time.
Not everyone might share my sensitivity to lack of movement. Still, a quick search into the habits of the most successful people will tell you that many people will link their productivity with their commitment to movement. In 2016, Fast Company‘s Michael Grothaus conducted an unscientific experiment on himself to find out how his brain would fare after a month of exercise. The first week, he ran for 45 minutes. He wrote, “immediately after my runs I would feel exceptionally clearheaded, and throughout the remainder of the day I felt like I had a focus that stuck with me even when I was sedentary.”
But what exactly happens to your brain when you break a sweat? What kind of exercise should you do if you want to get the most benefit to not only your body but also your brain? Most importantly, how long do you really need to move each week to be a more mentally resilient and productive individual? Fast Company caught up with two scientists who research exercise and the brain to find out.
How exercise affects your brain
Wendy Suzuki is a neuroscientist at New York University and the cofounder and CEO of BrainBody—a B2B business that quantifies exercise-enhanced brain functions using a cognitive analytics platform. Her interest in exercise and the brain started when she decided to incorporate daily movements into her schedule. As she told Fast Company back in 2016, she’d been on a river rafting trip to Peru, and realized that she was the weakest person in the group, despite being in her mid-thirties. When she got back to New York, she vowed to change her routine of spending all her time in the lab and started exercising regularly. She noticed a significant difference in her concentration levels and shifted her research focus to exercise and cognitive function.
When it comes to the benefits of exercise, “there are immediate effects, long term effects, and prospective effects,” says Suzuki. “I like to say that every time you work out, it’s like you’re giving your brain a wonderfully enhancing bubble bath.” Every time you do some movement that makes your heart rate goes up, “that stimulates the release of a wide range of neurochemicals and neurotransmitters, growth factors. These include serotonin, dopamine, endorphins. All of this relates to a better mood and higher energy score.”
The long-term effect of exercise, according to Suzuki, has to do with its impact on the hippocampus and prefrontal cortex, the only two areas where new brain cells are born in adulthood. The hippocampus is critical for one’s memory and is one of the areas most susceptible to aging. The prefrontal cortex is the part of our brains that are responsible for problem solving and coming up with strategies. Exercise stimulates growth factors and stores up cells in both parts of the brain. “You are protecting your brain from aging and neurodegenerative diseases,” says Suzuki. The prospective effect, says Suzuki, is that you’ll continue to see better brain function for a long time.
Finding an exercise regimen for optimal brain health
So, just how much exercise does one need to do for the brain benefits to kick in? A recent study published in Mayo Clinic Proceedings from the German Center of Neurodegenerative Disease suggested that 150 minutes of “moderate and regular exercise” a week can slow down cognitive decline in the brain. A 2018 study published by The Lancet Psychiatry found that people who exercised for 45 minutes for three to five times a week saw the most significant benefits to their mental health. Adam Chekroud, one of the authors of the study and an assistant professor of psychiatry at Yale University, says that after one goes beyond that threshold, the improvements are minimal.
But it’s one thing to recommend what might work for most people, and another to determine the minimum (or optimum) exercise regimen for every individual to improve one’s brain function. Suzuki says that one of the most common questions she gets asked is, what’s the least amount of exercise that one has to do to see a benefit? When she realized that her research wasn’t geared up to answer that question, she decided to start BrainBody. The company is still in “very early stages,” Suzuki says, but has been testing how different types of exercise, from low-impact to high, generate different benefits for the brain. Naturally, Suzuki was the first guinea pig, and she reported that every kind of workout provided some sort of brain benefits—just in “different flavors.” Ultimately, she hopes to be able to prescribe a specific exercise regimen to individuals that would have the maximum benefits on the brain and help protect cognitive decline.
Both Suzuki and Chekroud stresses that some exercise—no matter what form—is always better than nothing. While Suzuki herself aims to work out between five to six times a week, her workout sessions can last anytime between 10 to 45 minutes, depending on the time she has available.
Your brain and your body “really need regular physical activity” for it to operate at its best, says Suzuki. And it doesn’t need to be a strenuous, Barry’s Bootcamp-style workout. Any movement that increases the heart rate has the potential to yield the brain benefit she describes, including a power walk. Says Suzuki, “exercise is like a supercharged 401K for your brain.”