University of Tsukuba researchers found that running at moderate intensity for only 10 minutes increases local blood flow to the various loci in the bilateral prefrontal cortex. This is the part of the brain that plays a crucial role in controlling mood and executive functions. “Given that running is a whole-body locomotive exercise, it may confer more mental health benefits (by stimulating the brain) compared to other forms of exercise, such as cycling,” says study author Hideaki Soya, PhD, professor and director of the Laboratory of Exercise Biochemistry and Sport Neuroscience at the University of Tsukuba. No previous studies focused solely on the neuronal responses behind running’s benefits on mood and cognition, Soya adds. So his team’s experiment set out to look at this in depth.
The Study in Detail
The researchers used the well-established Stroop Color-Word Test, which requires participants to view a list of words that are printed in a different color than the meaning of the word. For instance, the word “green” is printed in red. Participants name the color of the word—not the word itself—as fast as they can. It can be used to measure a person’s selective attention capacity and processing speed, among other cognitive skills. The results show that after 10 minutes of moderate-intensity running, participants had a significant reduction in Stroop interference effect time. But that wasn’t the only benefit. “A 10-minute single-bout of moderate-intensity running elicits not only positive mood, but also executive function, accompanied by increased blood flow to the brain implicated in inhibitory control and mood regulation,” says Soya. David Linden, PhD, professor of neuroscience at Johns Hopkins and the author of Unique: The New Science of Human Individuality, points out that these findings aren’t actually new. The main difference between this study and previous research is that they used running instead of an exercise bike, and saw slightly different patterns of brain activation afterwards, Linden notes. “These patterns of brain activation are merely correlates—we don’t know that they are the basis for cognitive or mood improvements,” he adds. Nonetheless, the researchers hope their findings may contribute to the development of a wider range of treatment recommendations to benefit mental health. “We hope our findings encourage people to exercise—at the very least to do 10 minutes of moderate-intensity running to keep their body and brain fit,” says Soya.
Mental Health Benefits of Running
Many runners talk about experiencing “runner’s high”—but is there any science behind it? “People feel good and accomplished after running, but euphoria is rare,” says Linden. In fact, he reveals that only about 1 in 20 people actually report euphoria from running. It’s an ongoing argument between scientists, he says. Some of the so-called “euphoria” is probably improved blood flow to the brain, and the production of the brain’s own marijuana-like molecules (called endocannabinoids) may also be a factor. “Endorphins were once thought to be involved, but the evidence is now trending against that hypothesis,” Linden adds. Whether “runner’s high” is genuine or not, there’s solid science to back up the antidepressant effects of exercise. One systematic review, published in 2019, found that aerobic exercise improves clinically diagnosed major depression compared with antidepressant medication. “There’s nothing special about running,” Linden says. “Any aerobic exercise has anti-depressive effects for people of all ages and helps reduce cognitive decline as we age.”
