More than a decade ago, several groups of scientists working independently demonstrated conclusively that exercise stimulates the development of new brain cells. A whole lot of research since then has been largely unsuccessful at specifying how much exercise is required to get your brain blooming. Now, we at least know what kind of exercise does the trick. But, first…
Gretchen Reynolds, the “Science of Fitness” expert for the New York Times (www.nytimes.com/physed) recently reported the method and results of a Brain & Behavior study (actually, a Behavior & Brain study) led by researchers at National Cheng Kung University in Taiwan. First, the researchers taught two groups of mice to swim a water maze. One group wore little yellow Speedos. The other group wore blue. (Joke.) Then each group learned how to escape from an unpleasant stimulus. Next the mice in each group were put on an exercise regimen for four weeks. But, each group had a different regimen. One group was allowed to run at their own pace on “rodent wheels.” [The B&B Blogger was bemused to learn that the prevailing term, "gerbil wheels," has been politically corrected.] The other group was required to run faster and longer at speeds and durations determined by the scientists. So, sequentially, it went like this:
| Yellow group |
Learn water maze |
Learn escape task |
Run at own pace |
| Blue group |
Learn water maze |
Learn escape task |
Run for your life |
After the exercise component, both groups of mice were tested in the water maze. And, both groups did better than they had done during training. Then it was time for testing in the more cognitively challenging escape task. The Yellow Group did about the same as they had during training. However, the Blue Group did MUCH better than they had in the training session. Ah, hah!
In a critical final part of the study, especially for the mice, the brain of each mouse was examined micro-microscopically. The little noggins of the Yellow Group (the self-trained subjects) showed evidence of molecular changes in part of their brains. But, not to be outdone, the Blue Group showed such evidence in several parts of their brains. The researchers concluded that “Our results support the notion that different forms of exercise induce neuroplasticity changes in different brain regions.” In an apparent show of solidarity (and humility on the part of the Blues), neither group of mice commented on the findings during the subject debriefing phase of the study.
Reynolds reported on a second study, one that was published in the Journal of the American College of Sports Medicine. In this research, all student-subjects participated in a once-a-day routine in three, rotating conditions: One third of the students would sit comfortably for 30 minutes, another third would run for 30 minutes, and the final group would lift weights for 30 minutes. Each day when the students returned, they would be randomly assigned to one of the three groups. At the end of each day’s session, all students participated in a test in which the task was to pick out certain letters as they flashed by quickly on a screen. The B&B Blogger sadly regrets to report that sitting around comfortably had no effect on cognitive ability as measured by the “letters test.” On the plus side, there were also no changes for weight-lifting. However, students who had run for 30 minutes performed consistently higher. So, it’s not just exercise that makes you smarter, it’s a particular type of exercise.
While the evidence isn’t conclusive, it appears that it’s aerobic exercise that acts like smart pills. Why? So far, the guess is that healthy bodies have little bits of, well, brain fertilizer throughout the blood stream. The key is to get as many of the fertilizer bits as possible to the brain – which aerobic exercise does. Weight-lifting, on the other hand, causes the fertilizer to stay in the muscles that are being worked, helping them, not your brain, to grow.
Other studies have shown a dramatic positive effect of aerobic exercise on stress reduction, relief from depression, satisfaction with marriage and general life expectancy. So, it’s pretty much of a no-brainer (so to speak). Aerobic exercise is very good for you. In fact, it’s often claimed that regular aerobic exercise can add as much as 10 years to your life – though scientists seldom point out that you spend those 10 years running!
Original references for any studies, books or articles cited by the Brain and Behavior Blogger can be obtained by contact with his very dear friend, Dr. Rob Snyder (r.snyder@tier1performance.com), an organizational psychologist with a severe neuroscience-research reading habit.
