Physical Activity Boosts Brain Power
Multiple studies have shown that exercise is good for the body and mind. New research indicates it actually slows aging-related reduction of total brain volume and the volume of gray matter, which is associated with age-related cognitive decline.
The study involved brain scans on 2,013 people in Germany, ranging in age from 21 to 84, along with measurements of their cardiorespiratory fitness levels taken during exercise-bike workouts.
“Cardiorespiratory fitness was positively associated with gray matter volume, total brain volume, and specific gray matter and white matter clusters in brain areas not primarily involved in movement processing,” the researchers report in the January issue of the Mayo Clinic Proceedings. “The results suggest cardiorespiratory exercise may contribute to improved brain health and decelerate a decline in gray matter,” according to a statement from the journal.
“This provides indirect evidence that aerobic exercise can have a positive impact on cognitive function in addition to physical conditioning,” says Dr. Ronald Petersen, a Mayo Clinic neurologist who co-wrote an editorial on the findings. “Another important feature of the study is that these results may apply to older adults, as well. There is good evidence for the value of exercise in midlife, but it is encouraging that there can be positive effects on the brain in later life as well.”
Gray matter is made up of cell bodies, and white matter consists of nerve fibers that connect areas of gray matter.
“This is another piece of the puzzle showing physical activity and physical fitness is protective against aging-related cognitive decline,” says Dr. Michael Joyner, Mayo Clinic anesthesiologist and physiologist and co-author of the editorial. “There’s already good epidemiological evidence for this, as well as emerging data showing that physical activity and fitness are associated with improved brain blood vessel function. This paper is important because of the volumetric data showing an effect on brain structure.”
The Mayo experts suggest people get at least 150 minutes a week of moderate physical activity, the same as federal guidelines. This can include brisk walking or any other activity that elevates the heart rate.
The findings build on other studies linking exercise to improved cognitive ability, in young and old alike. Research shows that exercise releases chemicals that help grow new blood vessels in the brain and help keep brain cells healthy. A broad analysis of several studies found exercise positively affects the volume of the hippocampus, a part of the brain related to learning and verbal memory.
A study last year put sedentary people from age 20 to 67 on an exercise program involving moderate aerobic workouts four days a week for six months. Compared to a control group, the exercise group improved scores on tests measuring executive function — the ability to pay attention, organize and achieve goals, and an outer layer of their brains linked to executive function grew thicker, a sign of improvement. The improvements, detailed in the journal Neurology, were seen across all ages.
“The people who exercised were testing as if they were about 10 years younger at age 40 and about 20 years younger at age 60,” said study leader Yaakov Stern, PhD, a professor of neuropsychology at Columbia University.