Exercise is good for the brain. We know that. But most studies of exercise and brain health have focused on the effects of running, walking or other aerobic activities.
Now a new experiment suggests that light resistance training may also slow the age-related shrinking of some parts of our brains.
Our brains are dynamic organs, adding and shedding neurons and connections throughout our lifetimes. They remodel and repair themselves constantly, in response to our lifestyles, including whether and how we exercise.
But they remain, like the rest of our bodies, vulnerable to the passage of time. Many neurological studies have found that, by late middle age, most of us have begun developing age-related holes or lesions in our brains’ white matter, which is the material that connects and passes messages between brain regions.
These lesions are usually asymptomatic at first; they show up on brain scans before someone notices any waning of his or her memory or thinking skills. But the lesions can widen and multiply as the years go by, shrinking our white matter and affecting our thinking. Neurological studies have found that older people with many lesions tend to have worse cognitive abilities than those whose white matter is relatively intact.
Past studies have suggested that regular, moderate aerobic exercise such as walking may slow the progression of white matter lesions in older people.
But Teresa Liu-Ambrose, a professor of physical therapy and director of the Aging, Mobility, and Cognitive Neuroscience Laboratory at the University of British Columbia in Vancouver, wondered whether other types of exercise would also be beneficial for white matter.
In particular, she was interested in weight training, because weight training strengthens and builds muscles.
The results of the study found that women who concentrated on balance and flexibility showed progression in the number and size of the lesions in their white matter. So did the women who had weight trained once per week.
But those who had lifted weights twice per week showed significantly less shrinkage and tattering of their white matter. Their lesions had grown and multiplied somewhat, but not nearly as much.
Dr. Liu-Amrbrose and her colleagues did not however closely examine whether differences in the women’s white matter translated into meaningful differences in their ability to think. They also hope to learn more about how weight training affects white matter.
Exercise, including weight training, clearly “has benefit for the brain,” Dr. Liu-Ambrose said.”However we are just really now gaining an appreciation for how impactful exercise can be.”
October 21, 2015