- Exercise benefits both body and brain health, but how vigorous does that exercise need to be to have results?
- A new study suggests that even a small amount of exercise that barely raises the heart rate, such as very slow running, may have cognitive and mood benefits.
- In a small group of healthy people, researchers found that short, slow jogs induced a positive mood and promoted executive function in the brain’s prefrontal cortex, an area that is important for mood and cognition.
Don’t like building up a sweat or spending hours in the gym? Then the findings of a new study could be good news for you.
Researchers have found that even running very slowly for only 10 minutes may improve your mood and benefit your brain health.
In their study, published in Imaging Neuroscience, researchers from the University of Tsukuba, Japan, found that a very slow 10-minute run on a treadmill significantly enhanced mood and cognitive test scores in healthy people, when compared with their scores after a 10-minute rest.
Vernon Williams, MD, a sports neurologist and founding director of the Center for Sports Neurology and Pain Medicine at Cedars-Sinai Orthopaedics and Sports Medicine in Los Angeles and B-ASE Performance, Inc., not involved in the study, welcomed the findings.
Williams told Medical News Today:
“Previously,” he added, “it was thought there were thresholds related to frequency, duration, and consistency for long-term and sustained cognitive benefit. This current study suggests, however, that there is at least a short-term benefit from even lower levels of activity, not necessarily traditionally viewed as formal ‘exercise’.”
The researchers recruited 24 young Japanese adults, 13 men and 11 women, all in their early 20s, and with no health conditions. All were nonsmokers, were right-hand dominant and had normal or corrected-to-normal vision and healthy BMI (body mass index).
The participants were randomly assigned to two groups, which took part in two separate sessions on different days.
In one session, they sat for 10 minutes on a chair placed on a stationary treadmill; in the other, they jogged very slowly — 3-6 kilometers per hour (km/h), or 35% of their maximum exertion (VO2 max) — on the treadmill for 10 minutes. Before and after both the rest and the light exercise, they completed mood and cognitive tests.
Researchers used an event-related version of the color-word Stroop task (CWST) to assess cognitive function. To assess mood they used the two-dimensional mood scale (TDMS), a mood scale that uses eight words describing arousal and pleasure states: energetic, lively, lethargic, listless, relaxed, calm, irritated, and nervous.
During a separate 2-minute run, the researchers measured head acceleration to assess the up and down movement of the head. And during cognitive testing, they also measured blood oxygenation as a measure of brain activity.
After running, participants reported significant improvements in their mood, including greater alertness and feelings of pleasure, as well as achieving improved reaction times on the test of attention and self-control (CWST).
They also had a stronger oxygen-rich blood signal during cognitive testing in two areas of the left prefrontal cortex of the brain after running than after resting.
“When we engage in physical activity, blood flow to the brain increases and delivers vital oxygen and nutrients. The enhanced circulation supports neurogenesis — creating new brain cells — particularly in the hippocampus, a region crucial for learning and memory. Furthermore, exercise triggers the release of endorphins and neurotransmitters with mood-boosting and pain-relieving effects, often contributing to that post-workout feeling of well-being.”
Gentle exercise, as in this study, does not increase blood flow as much as more vigorous exercise, so the study authors suggest another mechanism for the brain effects.
“The positive relationship between head acceleration and improved mood may be one of the underlying mechanisms through which very slow running promotes mental health,” they hypothesize.
This suggestion is supported by an earlier study in rats and mice, which found that head movements influenced the function of nerve cells in the brain involved in learning, cognition and mood, and suggests that gentler movements may be more beneficial for the brain than vigorous ones.
The authors acknowledge that this small study had limitations. They suggest that further research should compare slow running with activities such as walking, and that studies should include people other than healthy young adults.
Williams cautioned that “the mechanisms associated with the cognitive benefits reported in this study as related to regular, everyday physical activity are less clear relative to neurotransmitter release and concentrations of factors with cognitive benefit.”
“However,” he added, “there may still be some association or correlation with increased blood flow to the brain’s frontal lobe associated with even ‘regular” physical activity. There is also likely some cognitive stimulation associated with regular physical activity that may also play a beneficial role.”
