Monday, November 12, 2007
One More Reason to Exercise....
One form of training, however, has been shown to maintain and improve brain health — physical exercise. In humans, exercise improves what scientists call “executive function,” the set of abilities that allows you to select behavior that’s appropriate to the situation, inhibit inappropriate behavior and focus on the job at hand in spite of distractions. Executive function includes basic functions like processing speed, response speed and working memory, the type used to remember a house number while walking from the car to a party.
Executive function starts to decline when people reach their 70s. But elderly people who have been athletic all their lives have much better executive function than sedentary people of the same age. This relationship might occur because people who are healthier tend to be more active, but that’s not the whole story. When inactive people get more exercise, even starting in their 70s, their executive function improves, as shown in a recent meta-analysis of 18 studies. One effective training program involves just 30 to 60 minutes of fast walking several times a week.
Exercise is also strongly associated with a reduced risk of dementia late in life. People who exercise regularly in middle age are one-third as likely to get Alzheimer’s disease in their 70s as those who did not exercise. Even people who begin exercising in their 60s have their risk reduced by half.
How might exercise help the brain? In people, fitness training slows the age-related shrinkage of the frontal cortex, which is important for executive function. In rodents, exercise increases the number of capillaries in the brain, which should improve blood flow, and therefore the availability of energy, to neurons. Exercise may also help the brain by improving cardiovascular health, preventing heart attacks and strokes that can cause brain damage. Finally, exercise causes the release of growth factors, proteins that increase the number of connections between neurons, and the birth of neurons in the hippocampus, a brain region important for memory. Any of these effects might improve cognitive performance, though it’s not known which ones are most important.
SOURCE
Executive function starts to decline when people reach their 70s. But elderly people who have been athletic all their lives have much better executive function than sedentary people of the same age. This relationship might occur because people who are healthier tend to be more active, but that’s not the whole story. When inactive people get more exercise, even starting in their 70s, their executive function improves, as shown in a recent meta-analysis of 18 studies. One effective training program involves just 30 to 60 minutes of fast walking several times a week.
Exercise is also strongly associated with a reduced risk of dementia late in life. People who exercise regularly in middle age are one-third as likely to get Alzheimer’s disease in their 70s as those who did not exercise. Even people who begin exercising in their 60s have their risk reduced by half.
How might exercise help the brain? In people, fitness training slows the age-related shrinkage of the frontal cortex, which is important for executive function. In rodents, exercise increases the number of capillaries in the brain, which should improve blood flow, and therefore the availability of energy, to neurons. Exercise may also help the brain by improving cardiovascular health, preventing heart attacks and strokes that can cause brain damage. Finally, exercise causes the release of growth factors, proteins that increase the number of connections between neurons, and the birth of neurons in the hippocampus, a brain region important for memory. Any of these effects might improve cognitive performance, though it’s not known which ones are most important.
SOURCE
Labels: brain, exercise, healthy living
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