Diet Write

by DietWrite,'s Diet and Fitness News Reporter

Subscribe to this feed

Can Exercise Make You Smarter?

Exercise does more than build muscles and help prevent heart disease. New science shows that it also boosts brainpower"and may offer hope in the battle against Alzheimer's.

Charles Hillman led an experiment that rounded up 259 Illinois third and fifth graders, measured their body-mass index and put them through classic PE routines: the "sit-and-reach," a brisk run and timed push-ups and sit-ups. Then he checked their physical abilities against their math and reading scores on a statewide standardized test. The kids with the fittest bodies were the ones with the fittest brains, even when factors such as socioeconomic status were taken into account. Sports, Hillman concluded, might indeed be boosting the students' intellect

Hillman's study, which will be published later this year, is part of a recent and rapidly growing movement in science showing that exercise can make people smarter. Last week, researchers announced that they had coaxed the human brain into growing new nerve cells, a process that for decades had been thought impossible, simply by putting subjects on a three-month aerobic-workout regimen. Other scientists have found that vigorous exercise can cause older nerve cells to form dense, interconnected webs that make the brain run faster and more efficiently. And there are clues that physical activity can stave off the beginnings of Alzheimer's disease, ADHD and other cognitive disorders.

Scientists have always suspected as much, although they have not been able to prove it. Long ago, researchers figured out that aerobic exercise helps the heart pump more blood to the brain, along with the rest of the body. More blood means more oxygen, and thus better-nourished brain cells. For decades, that has been the only link between athletic and mental prowess that science has been able to demonstrate with any degree of certainty.

Now, however, armed with brain-scanning tools and a sophisticated understanding of biochemistry, researchers are realizing that the mental effects of exercise are far more profound and complex than they once thought. The process starts in the muscles. Every time a bicep or quad contracts and releases, it sends out chemicals that travel through the bloodstream, across the blood-brain barrier and into the brain itself.

With regular exercise, the body builds up its levels of BDNF, and the brain's nerve cells start to branch out, join together and communicate with each other in new ways. This is the process that underlies learning: every change in the junctions between brain cells signifies a new fact or skill that's been picked up and stowed away for future use. BDNF makes that process possible. Brains with more of it have a greater capacity for knowledge. On the other hand, says UCLA neuroscientist Fernando Gómez-Pinilla, a brain that's low on BDNF shuts itself off to new information.

Most people maintain fairly constant levels of BDNF in adulthood. But as they age, their individual neurons slowly start to die off. Until the mid-'90s, scientists thought the loss was permanent"that the brain couldn't make new nerve cells to replace the dead ones. But animal studies over the last decade have overturned that assumption, showing that "neurogenesis" in some parts of the brain can be induced easily with exercise.

With scanning technology, Arthur Kramer, a psychologist at the University of Illinois, has found that exercise causes the frontal lobes to increase in size. And in dozens of previous studies of men and women in their 60s and 70s, brisk walking and other aero-bic workouts have yielded improvements in executive functioning. Subjects have fared better on psychological tests, answering questions more accurately and quickly. With the new brain studies, researchers can now begin to explain why.

Get off the treadmill after a half-hour workout, says Hillman, and "within 48 minutes" your brain will be in better shape. But alas, these benefits are somewhat transient. Like weight, mental fitness has to be maintained. New neurons, and the connections between them, will stick around for years, but within a month of inactivity, "the astrocytes shrink down again, and then the neurons don't function as well anymore," says William Greenough, a psychologist at the University of Illinois. Let your body go, then, and your brain will follow.

To keep the effects, you've got to keep working out. "If you're thinking that by exercising at age 20 you're going to have some effect on what you're like at age 70," Greenough adds, you'd better be willing to commit to 50 years of hitting the gym.

Unless, that is, you're a kid. Most studies of exercise and cognition have focused on older people but the effects of physical exertion on the brain aren't limited to that group at all. Exercise probably has "a more long-lasting effect on brains that are still developing," says Phil Tomporowski, a professor of exercise science at the University of Georgia. This won't surprise parents of kids with ADHD, many of whom already use physical activity as a substitute or supplement for drugs.

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 is that 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.

Scientists will have to answer 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 ...    Continue

1 | 2    Next Page

Post a Comment

Hot Topics

diet, weight loss, fitness, motivation, abs, restaurants, health, calories, stress, challenge, gyms, support, goals, points, exercise, metabolism, food, recipe

Most Popular Blogs

» Longer, Leaner Thighs: 5 Best Exercises
» 4 Creative Ways to Drink More Water!
» Best Vitamins Dieters Not Getting
» The Dangerous Escape Food Provides
» Janel Hits The Farmers Market

Highest Rated Blogs

» Top 3 Recipes for Terrific Weight Loss
» 4 Reasons Why Your Diet Keeps Failing You
» 6 Amazing Health Benefits of Calcium
» Cutting Sugar to Make a Difference Losing Weight
» Shed Pounds! 4 Steps for Your Weight Loss Journey

Sign up for our free diet newsletter
We respect your privacy. We will never share your email address with a 3rd party for any reason.