Neuroscientists know that aerobic exercise enhances brain function but have been reconsidering some previous theories about how and why. "Almost nothing in the brain gets done by one area -- it's more of a circuit," says the Beckman Institute's Arthur Kramer. Increasingly, studies have been examining the effects of exercise on white matter, which holds the brain's circuitry, in maintaining robust connections throughout all brain networks.
Brain Networks and Circuitry
In the past, neuroscientists have focused too much on the brain's gray matter, which contains neurons, and too little on white matter, where the interconnections that carry information throughout the brain's regional networks are found, says the lead author of an Australian study published February 2011 in the "Journal of Neuroscience." Speaking to "Psychology and Sociology" magazine, Perminder Sachdev of the University of New South Wales said, "We all know what happens when road or phone networks get clogged or interrupted. It's much the same with the brain." Connectivity declines with age, slowing the speed of information processing and potentially interfering with cognitive functions, Sachdev adds.
The "Couch Potato" Study
A year-long study of 65 "professional couch potatoes" between the ages of 59 and 80 examined the effects of aerobic exercise on white matter. Published in "Frontiers in Aging Neuroscience" on August 26, 2010, researchers led by Arthur Kramer, director of the University of Illinois' Beckman Institute, divided participants into two groups. Members of one walked at their own pace for 40 minutes three times a week while the others only did stretches. Significant improvements in the brain connectivity of the walkers were noted but no changes found in the brains of the stretchers. Walkers also out-performed stretchers in cognitive tasks. Even moderate exercise helps enhance connectivity of brain circuits, improving "executive control tasks, things like planning, scheduling, dealing with ambiguity, working memory and multitasking," Kramer said.
Exercise Improves Academic Scores
After a Chicago-area high school introduced a program that allowed students to control their own fitness activities, the math and reading scores of those who exercised immediately before being tested rose by 20 percent, reported "GradPSYCH" magazine, the graduate student publication of the American Psychological Association, in January 2010. This dramatic improvement in academic performance prompted guidance counselors at Napierville Central High School to urge students to work out right before classes in their most difficult subjects. Alison Miller, author of "Finish Your Dissertation Once and for All," published by the APA in 2008, encourages overworked grad students to incorporate "exercise snacks" into their daily routines, running, walking or cycling whenever they have the opportunity.
"Miracle-Gro for the Brain"
John J. Ratey, professor of psychiatry at Harvard Medical School and the author of "Spark: The Revolutionary New Science of Exercise and the Brain," calls a protein produced inside nerve cells, brain-derived neurotrophic factor, "Miracle-Gro for the brain." Studies show that running increases production of BDNF in mice, and the faster they run, the more BDNF they produce. This nourishment is especially beneficial to the hippocampus region, which Ratey calls "the Grand Central Station for memory." Aerobic exercise also increases heart rate, allowing the blood to deliver more oxygen to the brain and further sharpening mental function, Ratey says.
References
- "Frontiers of Aging Neuroscience"; Plasticity of Brain Networks in a Randomized Intervention...; Arthur F. Kramer et al.; August 26, 2010
- "Neuroscience News"; Moderate Exercise Enhances Connectivity in Brain Circuits; August 27, 2010
- American Psychological Association: "GradPSYCH Magazine"; Fitting in Fitness; Amy Novotney; January 2010
- "Psychology and Sociology"; Brain 'Network Maps' Reveal Clue to Mental Decline in Old Age; February 8, 2011
- "Spark: The Revolutionary New Science of Exercise and the Brain"; John J. Ratey; 2008
- Stem Cell Institute; Review of "Physical Exercise Stimulates Neural Stem Cells and Sharpens Cognitive Function"; January 8, 2009
