Multiple studies have documented a positive correlation between exercise and brain health. Researchers have shown that exercise may delay both the onset and severity of dementia and Alzheimer’s disease. Exercise benefits are seen even when the exercise regimen is initiated later in life. Although the correlation is strong, researchers are still puzzled why. The answer may lie in a specific hormone called irisin.
Irisin is a hormone produced by muscles during exercise. There appears to be a relationship between irisin release and the intensity of exercise – the greater the intensity, the more irisin is released. A recent study may help explain the relationship between irisin and brain health. During exercise irisin is released and travels to the brain. High levels of brain irisin were associated with a lack of dementia.
In this study, researcher’s injected irisin into the brains of mice specifically bred to develop dementia. They found there was a significant improvement in memory skills. They repeated the study in mice trained to exercise and found high levels of irisin was also associated with an ability to fight off the metabolic precursors of Alzheimer's disease.
Although this work will have to be confirmed in human studies, the bottom line – exercise not only makes us feel good through the release of endorphins but it may play a significant role in maintaining memory function. You no longer have an excuse for misplacing your running shoes.
