Being nagged about exercise isn't fun or motivating. Plus, it's cold out there in a lot of America. So how can you convince yourself to do what you know you should do: move more?

Forget guilt and pep talks. Maybe science is the answer. At least that's one conclusion you might draw from a talk given by Harvard psychiatrist and author John Ratey as part of MIT Media Lab's Wellbeing Seminar Series last year.

Super detailed, the hour-long deep dive into the science of how exercise positively affects the brain is pretty much guaranteed to make even confirmed couch potatoes want to go for jog.

"We need to move," says Ratey of our evolutionary baggage, early in the talk. "It's only 10,000 years ago that we were hunter-gatherers and we moved anywhere from 10 to 14 miles a day."

That's the bottom line for physical fitness, but science is beginning to show that it's equally true for our mental health. Ratey lays out an incredible amount of research showing the amazing things exercise does for our mood and cognitive function, as well as exactly how these positive effects work.


These days, test-obsessed schools are often swapping gym for academics. Bad idea, insists Ratey. Why? Not just because sitting around makes kids fat and unhealthy. "The more fit you are, the better student you are," he explains.

There are tons of studies to back this up, including one looking at 2.6 million kids in Texas, which found a strong correlation between fitness levels and grades. That's regardless of demographic factors like race, gender, or parents' income.

But the real clincher, according to Ratey, is a Swedish study that looked at 1.2 million boys, who were evaluated at 15 for fitness and IQ, and then tested again when they began compulsory military service at 18. The results: if they got fitter, they also got smarter. That was even true of identical twins. If one exercised but the other didn't, the one that moved showed a cognitive benefit that the one who sat around didn't. This was clearly down to the exercise and not anything inborn. "We know exercise improves our ability to think," concludes Ratey.

Looking for motivation to move today? Even just standing up starts positive processes in the body and brain. "We know from studies, when we stand our brains are a little bit better, maybe 7 percent better than when we're sitting," Ratey says. Regular exercise is best, but just standing up is a good start.


Exercise just doesn't fire up our brains, making us smarter. It also changes the chemistry inside our skulls, making us happier. In fact, according to one study out of Duke, exercise works just as well at treating depression as the common anti-depressant Zoloft.

"Exercise does the same kind of thing that many of our medicines do. A bout of exercise is like taking a little bit of Prozac and a little bit of Ritalin," explains Ratey, noting that, like drugs such as Zoloft, exercise increases the amount of neurotransmitters in our brains.

Less stressed.

That's not the only way exercise physically affects our brains, impacting our mental health. It also speeds the incredible process of neurogenesis, actually helping us grow new brain cells. Meditation, learning, and laughing all increase the amount of new cells being born, but exercise is best, Ratey says.

These new cells tend to damp down our stress response. "The fitter you are, the more stress it takes to get you stressed," reports Ratey. And other physical processes combine to help make exercise a fabulous stress buster. Apparently, working out also spurs the release of something called ANP, for instance, which helps damp down panic.

Listening to Ratey, it's easy to be convinced that you really should exercise more -- not just for your body, but also for your brain. But what if you worry these research results aren't for you -- that you're too old or unfit to start an exercise program now?

Tough luck, responds Ratey, pointing to Mr. Singh, a marathoner who started running at the ripe age of 89 and continued past his 100th birthday. "Evolution has built in our ability to change at any time if we go for it," declares Ratey. "There's really no excuse."

Want many more details? Then watch the complete talk below.


OK, I am going to go for a run now (seriously!). How about you?