Even Very Slow Running Can Benefit The Brain, Study Suggests
A 10-minute jog at a pace barely faster than walking may still be enough to give the brain a short-term boost, according to new research examining how very slow running affects mood and cognitive function.
Researchers at the University of Tsukuba in Japan found that even running at extremely low speeds was associated with improved mood, faster performance on a test of attention and self-control, and increased activity in parts of the brain’s prefrontal cortex. The findings were published in Imaging Neuroscience.
The researchers recruited 24 healthy young adults and had each participant spend 10 minutes running on a treadmill at a slow pace of roughly 1.9 to 3.7 miles per hour (3 to 6 kilometers per hour).
During the treadmill sessions, average heart rates among both male and female participants ranged from 104 to 107 beats per minute. The researchers compared those sessions with separate days when participants spent 10 minutes sitting still.
Following the slow-running sessions, participants reported significant improvements in mood, including feeling more alert and more pleasant than they did after sitting.
They also performed better on a cognitive test measuring attention and self-control, responding more quickly after running than after sitting still.
During the tests, participants wore headsets that monitored changes in oxygenated hemoglobin near the surface of the brain.
Although the technique is less precise than an MRI, it can provide a general indication of which areas of the brain become more active during certain tasks.
After participants ran, the headsets detected a stronger oxygen-rich blood signal in two areas of the left prefrontal cortex while they completed the cognitive tests. The region plays an important role in both cognition and mood.
Some of the same researchers had previously found that 10 minutes of moderate-intensity running could increase activation in the prefrontal cortex. The new experiment suggests that those effects may also appear at much lower running intensities.
There are several limitations to the findings. The study involved only 24 healthy young adults, so the results may not apply to people of different ages or health backgrounds.
It also examined only the immediate effects of a single 10-minute session, rather than the long-term effects of regularly running at a slow pace.
And because the researchers compared running with sitting rather than walking, the experiment cannot determine whether very slow running produces benefits that similarly gentle walking would not.
What causes the observed changes remains uncertain. One possibility is that running activates neural networks that project into the prefrontal cortex. Another involves the rhythmic movement of the head during a run.
Animal experiments have suggested that repeated up-and-down head movement may mechanically stimulate the brain, raising the possibility that head acceleration itself could contribute to some of the effects.
“This is a new and challenging hypothesis, and the exact neural circuitry involved in the positive effect of head acceleration on mood has not been identified and needs further investigation.”
The researchers found that, among participants in the study, greater head acceleration during very slow running was associated with higher levels of exercise-induced pleasure. Head acceleration accounted for about 17 percent of the variation in improved mood scores between participants.
“This discovery of the positive relationship between head acceleration and improved mood may be one of the underlying mechanisms through which very slow running promotes mental health.”
Previous studies examining low-intensity exercise and cognition have often focused on cycling, in part because researchers can more easily control the exercise intensity.
But cycling may not produce the same degree of rhythmic head movement as jogging, which could matter if head acceleration contributes to the effects observed in the new study.
The findings also raise a broader question about running’s role in human evolution.
Humans evolved to run long distances while upright on two legs, and endurance rather than speed may have helped early humans survive by allowing them to pursue large prey across the savannah.
The researchers suggest that the evolutionary importance of running could also be connected to the development of the human brain.
“It is interesting to hypothesize that human upright bipedal running is also strongly tied to the evolutionary expansion of the Homo sapiens’ frontal lobes and higher cognitive functions. Against this background, running may be viewed not simply as another exercise modality, but as a biologically foundational form of human movement with particular relevance to brain function.”
That evolutionary connection remains speculative, and the current experiment cannot establish that running played a role in the development of human cognition. Nor can the study determine the exact mechanism responsible for the changes researchers observed after exercise.
But the findings suggest that a run does not necessarily have to be fast or demanding to produce measurable short-term changes in mood, cognitive performance, and brain activity.
So on days when a run feels more like an awkward shuffle than a workout, it may still be doing something useful.
Moumita Basuroychowdhury is a Contributing Reporter at The National Digest. After earning an economics degree at Cornell University, she moved to NYC to pursue her MFA in creative writing. She enjoys reporting on science, business and culture news. You can reach her at moumita.b@thenationaldigest.com.
