Very slow running boosts mood after 10 minutes

A treadmill set the pace barely above a walk: 3–6 km/h for 10 minutes. After this very slow run, participants felt more pleasant and performed better on a Stroop interference task, a test of executive function.

The effort was deliberately light—approximately 35% of peak oxygen uptake, a measure of the body’s maximum ability to use oxygen during exercise. That matters because running is often treated as a demanding workout, while this protocol tested what happens when the physiological cost is small. The pace was close to walking, but the participants were still running.

The team used fNIRS, or functional near-infrared spectroscopy, to monitor activity in the prefrontal cortex, the brain region involved here in executive function and mood regulation. Activity rose most notably in the left dorsolateral prefrontal and left frontopolar cortices. Greater up-and-down movement of the runner’s head was also associated with a greater improvement in mood.

And so what, concretely? A brief, comfortable run could offer a practical way for people with low fitness levels—or those who find conventional exercise difficult—to support mood and executive function without a strenuous workout. The result is a laboratory finding from a controlled treadmill study, not evidence that every outdoor run will produce the same effect or that the benefit will persist.

The paper, published in Imaging Neuroscience, adds to earlier research cited by the researchers showing that 10 minutes of very light-intensity exercise can improve hippocampal-dependent memory. Together, the findings point toward a broader role for short, gentle exercise, while leaving the duration and real-world reach of the effects to be tested.