White matter tracts enable communication between areas of the brain, but like the rest of the body, they decline with age. However, research suggests that staying active may help to preserve the integrity of these tracts. Agnieszka Burzynska, a postdoctoral researcher at the University of Illinois, and colleagues used accelerometers to track physical activity in 88 healthy but “low-fit” participants aged 60 to 78. Results showed that older adults who engaged more often in light physical activity had greater structural integrity in the white-matter tracts of the temporal lobes, which play a key role in memory, language, and the processing of visual and auditory information. Conversely, those who spent more time sitting had lower structural integrity in the white-matter tracts connecting the hippocampus. “This relationship between the integrity of tracts connecting the hippocampus and sedentariness is significant even when we control for age, gender and aerobic fitness,” said Burzynska. “It suggests that the physiological effect of sitting too much, even if you still exercise at the end of the day for half an hour, will have a detrimental effect on your brain.”

Burzynska AZ, Chaddock-Heyman L, Voss MW, et al. Physical activity and cardiorespiratory fitness are beneficial for white matter in low-fit older adults. PLoS One. 2014 Sep 17;9(9):e107413.  For more visit http://www.eurekalert.org/pub_releases/2014-09/uoia-slp091614.php