How does exercise affect the older-adult brain?
Here’s another reason to keep moving into those later years. A study from PLOS ONE (doi: 10.1371/journal.pone.0134819) shows that older adults who are physically active have more variable brain activity at rest than those who are not active. Brain variability is associated with greater cognitive function, researchers say.
While links among physical activity, cardiorespiratory fitness and brain function have already been established, the purpose of this study was to determine the effects of sedentary, light, and moderate-to-vigorous activity on neural function. To gather activity data, the scientists fitted 100 participants aged 60-80 with accelerometers for 7 days. Oxygen consumption measurements determined cardiorespiratory fitness; and functional MRI showed how blood oxygen levels in the brain fluctuated over time, reflecting brain activity at rest. The researchers also assessed the integrity of each person's white-matter fibers, which carry nerve impulses and interconnect the brain.
“As an index of functional brain integrity we used spontaneous moment-to-moment variability in the blood oxygenation level-dependent signal (SDBOLD), known to be associated with better cognitive functioning in aging,” the authors explained.
The results? Older adults who participated in more physical activity, regardless of type (light, or moderate to vigorous), posted better brain scores than those who were less active. White-matter brain structure was healthier in the active groups.
“We demonstrated that older adults with greater overall [white matter] microstructure were those showing more light-intensity and moderate to vigorous physical activity and greater SDBOLD,” the authors said. “We conclude that SDBOLD is a promising correlate of functional brain health in aging.”