Stronger, Faster, Smarter

With that science in mind, many educators are now pushing for an overhaul of physical education in public schools. Teachers can ensure their students' success in other subjects, they argue, by making PE longer and more focused on brain-strengthening cardiovascular exercise. Inspired by Hillman's work, Kentucky State Sen. Katie Stine recently proposed a bill making a daily half hour of PE mandatory for kids up to eighth grade. It passed the Senate last month. And at schools in Naperville, Ill., students with poor verbal skills have started taking PE immediately before reading class. Their report cards, says Ratey, are already looking better.

The hope of educators isn't just that Johnny and Susie will do better on the SAT. There's a long-term goal as well. If kids develop a love of sport early in life, they're more likely to grow into active adults. And if they do, they may avoid a fate their grandparents are currently facing: a slow slide into mild cognitive impairment, followed by Alzheimer's. Gómez-Pinilla says that Americans' lazy lifestyles may be contributing to their high rates of the disease. Humans have evolved, he notes, to thrive on physical activity; without it, "our brains aren't doing what they're supposed to," and they go awry. Early studies suggest that people who exercise at least a few times a week tend to develop Alzheimer's less often and later than their more sedentary counterparts. There are clues at the level of the brain as well: one of the disease's first targets is the hippocampus.

More controversial is the proposal that exercise might slow the progression of Alzheimer's once it has taken hold. "By the time somebody has fairly well-developed Alzheimer's, it's probably too late," says Yaffe. "It's going to be difficult to get them into an exercise program at that point, and the damage may already be done." There's a grain of hope, however, to be found in animal studies. In mice that develop a disease that resembles Alzheimer's, a type of plaque similar to what's found in people builds up in the brain. Carl Cotman, a neuroscientist at the University of California, Irvine, examined those mice in 2005 and found that those who spent more time running on wheels fared better on memory tests. They also had lower levels of plaque in their brains, he says, possibly "because exercise caused them to produce less plaque and clear more of it."

That gives rise to the question: if exercise is such good medicine, could scientists someday distill its brain-powering effects into chemical form—a sort of "workout in a pill"? The result might end up resembling many of the drugs that scientists are currently developing to bolster memory in Alzheimer's patients. It would also surely appeal to people who aren't willing to drag themselves to the gym every other day. "There's a resistance to maintaining an exercise program, since it involves a lot of work. People just don't feel like it," says Ratey. "They're, like, 'I want it done fast, and I want it done now, and why should I have to labor over the treadmill?' " Small, the Columbia researcher, says many of his lab colleagues have started working out because of his study results. But, he adds, for his own part, he "would much rather find that biochemical link and think about how we might be able to reproduce the effect for the couch potatoes."

Before that can happen—way before that can happen—scientists will have to answer a number of nagging questions that remain. Chief among them is why some forms of exercise affect the brain far more than others. Most researchers have focused on aerobic exercise, "and they've ignored strength training" in the process, says Carole Lewis, a physical therapist and coauthor of the new book "Age-Defying Fitness." So far, though, for reasons that no one really understands, the few studies that have examined stretching, toning and weight lifting have found little to no effect on cognition. Researchers also don't have a clear idea of how much exercise is too much. "There are very good rules for how many hours a day you should work out, and how many days a week, and what kinds of rest periods you should take—but that's all with respect to the rest of your body," says Greenough. "As for the brain, it's just not known, and we need studies like that."

Finally, there's the question that's been dogging Charles Hillman since he first picked up a hockey stick: why, if jocks on average have more capable brains than the rest of the public, do they have an unfair reputation for being dumb? Why does a term like "scholar-athlete," which would have made so much sense to the ancient Greeks, get snickered at today? The reason, says Hillman, is found not in science but in common sense: some of our schools have failed young athletes by cutting them too much slack. "A lot of it comes from schools' giving them an easy road," he says. "Kids get this wholly inaccurate label because they're good at sports, and then too much emphasis is placed on their physical abilities at the expense of their mental abilities." Having a big, gorgeous, healthy brain isn't enough, of course; it also has to be full. For that, kids have to hit the library as well as the gym. "You can optimize your brain to learn," says Ratey, "but then you have to be in an environment where you can do that—and you have to want it." Sometimes, it's the "scholar," not the "athlete," who counts.

© 2007