More and more studies are showing how regular exercise benefits the brain, and in particular, the aging brain. What’s less clear is how exactly exercise counters the cognitive decline that comes with aging and diseases like Alzheimer’s.

Just 10 Minutes of Exercise a Week May Be Enough to Extend Your Life, Study Says0 seconds of 1 minute, 7 seconds 

To find out, for nearly a decade, Ozioma Okonkwo, assistant professor of medicine at the University of Wisconsin School of Medicine and Public Health and his colleagues have studied a unique group of middle-aged people at higher risk of developing Alzheimer’s. Through a series of studies, the team has been building knowledge about which biological processes seem to change with exercise. Okonkwo’s latest findings show that improvements in aerobic fitness mitigated one of the physiological brain changes associated with Alzheimer’s: the slowing down of how neurons breakdown glucose. The research, which has not been published yet, was presented at the annual meeting of the American Psychological Association on Aug. 9.

Okonkwo works with the 1,500 people on the Wisconsin Registry for Alzheimer’s Prevention (WRAP)—all of whom are cognitively normal, but have genes that put them at higher risk of developing Alzheimer’s, or have one or two parents who have been diagnosed with the disease, or both. In the latest study,Okonkwo recruited 23 people from the WRAP population who were not physically active. Eleven were asked to participate in an exercise regimen to improve their aerobic fitness for six months, and 12 served as the controlAll had their brains scanned to track Alzheimer’s-related brain changes including differences in how neurons metabolized glucose, since in people with Alzheimer’s glucose breakdown slows.“We are carrying our research full circle and beginning to demonstrate some causality,” says Okonkwo about the significance of his findings.In their previous work, he and his team identified a series of Alzheimer’s-related biological changes that seemed to be affected by exercise by comparing, retrospectively, people who were more physically active to those who were not.In this study, they showed that intervening with an exercise regimen could actually affect these processes. Taken together, his body of research is establishing exactly how physical activity contributes to significant changes in the biological processes that drive Alzheimer’s, and may even reduce the effect of strong risk factors such as age and genes linked to higher risk of neurodegenerative disease.