If you’ve ever thought about turning to running in order to improve your cardiovascular strength, but have a slightly lazy streak like me, you might want to rethink that decision. Recently, an MRI study has shown that endurance runners’ brains have greater functional connectivity than the brains of more sedentary individuals.
The revelation comes from an MRI study conducted by the University of Arizona, where researchers compared brain scans of young adult cross country runners to young adults who don’t exercise on a regular basis. The functional connectivity within several areas of the brain, (that is, the connections between distinct brain regions) were significantly greater in the runners. Great functional connectivity was especially shown in the crontal cortex, which is important for cognitive functions such as planning, decision-making, and the ability to switch between tasks.
The current findings were published in the journal Frontiers in Human Neuroscience and, although additional research is of course needed in order to determine whether these physical differences in brain connectivity result in differences in cognitive functioning, the findings help lay the groundwork for researchers to better understand how exercise affects the brain. The study was designed by UA running expert David Raichlen, an associate professor of anthropology, along with UA psychology professor Gene Alexander, who studies brain aging and Alzheimer’s disease as a member of the UA’s Evelyn McKnight brain institute.
“One of the things that drove this collaboration was that there has been a recent proliferation of studies, over the last 15 years, that have shown that physical activity and exercise can have a beneficial impact on the brain, but most of that work has been in older adults,” Raichlen said. “This question of what’s occurring in the brain at younger ages hasn’t really been explored in much depth, and it’s important,” he said. “Not only are we interested in the brain in what’s going on in the brain of young adults, but we know that there are things that you do across your lifespan that can impact what happens as you age, so it’s important to understand what’s happening in the brain at these younger ages.”
During the research, Raichlen and Alexander compared the MRI scans of a group of male cross country runners to the scans of young adult males who hadn’t engaged in any kind of organized athletic activity for at least a year. The participants all had comparable body mass index and educational levels and were roughly between the ages of 18 to 25. The scans measured resting state functional connectivity, which is what goes on in the brain while participants are awake but at rest, not engaging in any specific task.
The MRI study findings are shedding new light on the impact that running, as a particular form of exercise, is having on the brain. Previously, studies have shown that activities that require fine motor control, such as playing a musical instrument, or that require high levels of hand eye coordination, such as playing golf, can alter brain structure and function.
Up until now, however, few studies have looked at the effects of more repetitive athletic activities that don’t require much precise motor control – like running. Raichlen’s and Alexander’s findings suggest that these types of activities could have a similar effect. “The activities that people consider repetitive actually involve many complex cognitive functions – like planning and decision making – that may have effects on the brain,” Raichlen said.
Since functional connectivity often appears to be altered in aging adults, and particularly in those with Alzheimer’s or other neurodegenerative diseases. And what researchers learn from the brains of young adults could have implications for the possible prevention of age related cognitive decline later on. “One of the key questions that these results raise is whether what we’re seeing in young adults – in terms of the connectivity differences – imparts some benefit late in life,” said Alexander, who also is a professor of neuroscience and physiological sciences. “The areas of the brain where we saw more connectivity in runners are also the areas that are impacted as we age, so it really raises the question of whether being active as a young adult could be potentially beneficial and perhaps afford some resilience against the effects of aging and disease.”
