Can Exercise Make You Smarter?

Adam’s Journal

The other day, restless and unable to sleep, I got up early and did a long run before work. Although I expected to be fatigued, that day proved to be one of my most productive. In fact, I found myself working through my inbox with lightning speed, particularly in the morning immediately following the run.

Was this just a happy coincidence, or is there something about exercise that revs the brain up?


Dr. Prescott Prescribes

By this point, it’s not exactly news that exercise is good for the body. But with every passing day researchers are uncovering new evidence as to just how wide-ranging those beneficial effects can be, and scientists have now found good evidence that exercise improves cognition. In particular, aerobic exercise seems to give the brain a jolt.

In an experiment published in the journal of the American College of Sports Medicine, researchers asked students at the University of Illinois to memorize a string of letters and then pick them out from a list flashed at them. The students then spent 30 minutes doing one of three things: running, lifting weights or sitting quietly. They then retook the test.

The students who ran performed noticeably better on the test than the ones who lifted weights or did nothing. They even continued to outperform the others following a cool-down.

The same group of researchers also looked at cognitive performance in elderly subjects who engaged in a six-month program of either brisk walking or stretching. Again, they found that the brisk walkers improved their performance on tests of cognition while the stretchers didn’t.

Recent studies in laboratory mice have also looked at cognitive function and changes in brain structure. In particular, they’ve compared the effects of “rich” cognitive surroundings with exercise.

It’s true that even laboratory mice don’t read Tolstoy and listen to Brahms, but the researchers did their best to stimulate the animals’ minds by loading cages with goodies like plastic tunnels and nibble-able blocks. And while the rodents who were ensconced in Habitrails loved their toys, it turned out that the only thing that made any difference was whether the cage had a running wheel.

The animals that exercised had healthier brains and performed much better on cognitive tests than their sedentary counterparts. Mice that didn’t run, no matter how goodie-filled their cages, didn’t improve their test results.

If aerobic exercise boosts brainpower—and these studies suggest it does—it probably stems from the significantly increased blood flow that comes with vigorous workouts. Unlike weight lifting or stretching, a brisk walk or run appears to carry growth factors from other parts of the body to the brain, where the body forges new neurons and neural connections.

So next time we have a column to write, I’ll be sure to hit the gym first!