Exercise confers numerous physical benefits, such as increasing physical strength and stamina, and offers protection from certain diseases, such as heart disease. But scientists are now uncovering surprising ways in which exercise also boosts brain function. Exercise seems to directly affect brain structures and nerve cell growth and development.
Improves Thinking
Researchers are uncovering ways in which exercise improves thinking. In the 1990s, scientists discovered that adults can grow new neurons, or brain cells, throughout life. In a 2010 "Cell Stem Cell" study of rats' ability to grow neurons, Dr. Fred Gage and colleagues showed that rats who were allowed to run on wheels, later did better on running through mazes -- a test of their "rodent I.Q." -- as compared with rats who did not run on wheels. Exercise seems to have increased their ability to grow more neurons, which in turn improved their thinking. According to a 2008 review published in "The Cochrane Library," older adults who engaged in aerobic exercise showed improvement in thinking as well.
Protects Memory
As adults age, the brain shrinks in size, affecting memory, among other things. Research published in 2010 by Kirk I. Erickson, PhD, in the journal "Neurology," suggests that older people who walked about six to nine miles per week had larger brains and better memory than those who did not walk as much. The beneficial effects of exercise are not limited to older adults. In a 2010 study of children published in "Brain Research," researchers Art Kramer and Laura Chaddock at the University of Illinois, found that nine and 10 year olds who were more physically fit than their peers had larger hippocampi, the structure of the brain related to learning and memory.
Protects from Age-Related Declines
Physical exercise can keep your brain healthy with age and prevent diseases such as dementia. The aging circulatory system can reduce the blood supply to the neurons, creating cognitive deficits such as a decline in executive function. In the book, "Welcome to Your Brain," authors Sandra Aamodt, PhD and Sam Wang, PhD, note that exercise that elevates heart rate brings oxygen and glucose to the brain, improving executive function. In addition, the authors note that, compared with people who do not exercise, middle-aged people who exercise regularly are about one-third less likely to get Alzheimer's disease in their seventies. It is not too late to begin an exercise program and even people in their sixties who begin to exercise can reduce their risk of Alzheimer's as well.
Reduces Anxiety and Depression
Exercise offers benefits for mental health and seems to have immediate effects on mood, according to a March 2010 presentation by Jasper Smits at the annual conference of the Anxiety Disorder Association of America. Smits, director of the Anxiety Research and Treatment Program at Southern Methodist University in Dallas, and his colleague, Michael Otto, analyzed studies on the effects of exercise on depression and anxiety and concluded that exercise is effective in reducing both depression and anxiety symptoms. They theorize that exercise affects the neurotransmitters in the brain. For exercise to be effective, they suggest people perform 150 minutes of moderate-intensity or 75 minutes of high-intensity exercise per week.
References
- New York Times: Phys Ed: Your Brain on Exercise
- Science Daily: Aerobic Exercise Boosts Older Bodies and Minds, Review Suggests
- Science Daily: Children's Brain Development Is Linked to Physical Fitness, Research Finds
- Science Daily: Walk Much? It May Protect Your Memory Down the Road
- "Welcome to Your Brain"; Sandra Aamodt, PhD and Sam Wang, PhD; 2008.
- Science Daily: Mental Health Providers Should Prescribe Exercise More Often for Depression, Anxiety, Research Suggests
