“It is exercise alone that supports the spirits, and keeps the mind in vigor.”
—Cicero
“It is remarkable how one’s wits are sharpened by physical exercise.”
—Pliny
Everyone knows that exercise is good for you. Regular workouts can decrease the risk of heart disease, osteoarthritis, and Type II diabetes. Exercise can help you achieve or maintain a healthy Body Mass Index (BMI). But can it make you smarter? Research done both on school-age children and on older adults suggests that regular aerobic exercise does indeed have benefits for improving learning and cognitive abilities throughout life.
The nexus of the exercise-at-school movement is Naperville, Ill., a small, middle-class town with historically good schools and highly achieving students. In the mid 1990s, a visionary gym teacher named Phil Lawler wanted to test what he always believed to be true—that kids who were physically fit did better academically than the “couch potatoes.”
With the support of the district’s physical education (PE) coordinator, Paul Zientarski, Naperville made daily PE class mandatory for everyone. Some kids who were having difficulty in math were given extra workouts right before their remedial algebra class. According to a 2008 report published in Education Week, their test scores increased by 20.4 percent, while kids in the same class who opted out of extra workouts only improved by 3.9 percent.
An important point is that the Naperville PE classes are very individualistic. Kids are challenged to work out to their own target heart rate and achieve their own personal bests. Classes do not center on games with winners and losers, like dodgeball or basketball, but rather teach all kids how to be fit for life.
Epidemiological studies in California, where every student is required to complete a fitness assessment in grades 3, 5, and 7, drew conclusions similar to the Naperville study. When adjusted for socio-economic factors, these data also showed a positive correlation between a student’s aerobic fitness, healthy BMI scores and academic achievement.
Several epidemiological studies have shown a link between high levels of physical fitness in older adults and their cognitive abilities. Even in older adults who did not exercise regularly, a program of aerobic exercise has been shown to improve their basic mental skills.
A 2004 study by Colcombe, et al., published in the Proceedings of the National Academy of Sciences, tested the ability of older adults to focus their attention while brain activity was monitored by functional magnetic resonance imaging (fMRI). The test group participated in moderate aerobic activity (45-minute walks, three days per week) for six months, while the control group participated in non-aerobic stretching exercises for the same time. Results showed that the walking group scored higher in objective tests of paying attention and staying on task. The fMRI scans of their brains revealed higher activity in the frontal and parietal sections, which are known to control executive functions like planning, working memory, and multitasking. These are all areas that typically decline with advanced age.
It has long been known that laboratory rats kept in cages with exercise wheels perform much better on tasks of mental ability (like finding food hidden in a maze) than do those that are not able to exercise. In a 2008 review article Dr. Charles Hillman and colleagues at the University of Illinois discussed some reasons why this could be true. Dissections revealed that physically fit rats have more blood vessels throughout their brains.
Exercise causes increased blood flow, which brings more oxygen and other nutrients into the brain. Exercise also increased the number of nerve cells and of synapses, which are connections between nerve cells. Other researchers have shown that aerobic exercise increases production of a molecule called brain-derived neurotrophic factor (BDNF). BDNF is a precursor to other neurochemicals involved in mood regulation and executive function. In fact, in early 2009 scientists at the University of California, San Diego, published evidence that BDNF could reverse some cognitive decline in animals that have symptoms of Alzheimer’s disease.
While Cicero and Pliny had no way of knowing about brain biochemistry, they knew that physical exercise kept people mentally sharp. The unfortunate trend toward a more sedentary lifestyle has hidden this basic truth from many people today.
For further reading: Active Living Research, a publication of the Robert Wood Johnson Foundation, Fall 2007; Spark, by Dr. John Ratey & Eric Hagerman, 2008, Little, Brown & Co.