A brief workout may be all it takes to temporarily boost your brain power

A 20-minute session of moderate treadmill exercise helped younger and older men respond faster on a test of attention and self-control, according to a study published in Mental Health and Physical Activity. The findings suggest that even a brief period of movement may temporarily sharpen mental processing without reducing accuracy.

Exercise is often discussed in relation to long-term physical health, but researchers have also found that a single bout of exercise can affect the brain. One area of interest is inhibitory control—the ability to focus on what matters while ignoring distractions. This ability is important in everyday life, from driving safely to resisting impulses or staying focused during work.

Inhibitory control is commonly tested using the Stroop color-word task. In this task, people may see the word “red” printed in blue ink and must say the ink color rather than read the word. The task creates a mental conflict because reading the word is automatic, while naming the ink color requires control. Older adults often take longer on this kind of task, partly because processing speed and attention control can decline with age.

The researchers wanted to examine not only whether exercise improved task performance, but also what was happening in the brain during that improvement. Led by Kuo-Pin Wang of National Taiwan University, the team studied 51 healthy male adults. The sample included 28 younger adults, with an average age of 24.5 years, and 23 older adults, with an average age of 70.1 years. The researchers recruited only men to avoid potential confounding factors related to sex-specific physiological and hormonal responses to acute exercise.

Each participant completed two separate sessions. In one, they walked or ran on a treadmill for 20 minutes at moderate intensity, defined as 60% to 70% of heart-rate reserve. In the other, they watched a video while seated. The order was counterbalanced, meaning some participants exercised first while others completed the video condition first. After each session, participants performed the Stroop task while their brain activity was measured using electroencephalography, a non-invasive method that records electrical signals from the scalp.

The results showed that participants responded faster after exercise than after video watching. Importantly, this faster performance did not come at the expense of accuracy. In simple terms, exercise appeared to help participants work more quickly without making more mistakes. Older adults were still generally slower than younger adults and showed greater difficulty on the most conflicting trials, but both age groups benefited from exercise.

The brain recordings offered clues about why this may have happened. After exercise, the researchers found reduced early brain responses linked to initial visual processing and conflict monitoring. Later brain patterns suggested stronger attentional engagement and preparation for response.

The authors described this as a “dual-phase” effect. Exercise may reduce the mental effort needed at early stages while helping the brain allocate resources more effectively later. This dual-phase mechanism was observed across both younger and older adult groups.

As the researchers wrote, “even a single acute exercise session can transiently optimize neural efficiency.” In practical terms, this means a short period of exercise may briefly help the brain process information more efficiently, especially during tasks requiring focus and quick responses.

The authors noted several limitations. The study tested only one bout of exercise, so it cannot show whether repeated sessions would produce lasting changes. Because the study only recruited men, it is unclear if the results generalize to women. Another caveat is that the researchers did not test participants before each session, so faster responses after exercise could reflect a true exercise benefit, slower performance after prolonged sitting and video watching, or both.

The study, “Moving the body or watching the screen: 20-minute exercise modulates brain activity and enhances cognitive performance in younger and older male adults,” was authored by Kuo-Pin Wang, Li-Ju Chen, Chien-Lin Yu, Dong-Tai Chen, Tsung-Min Hung, and Shu-Shih Hsieh.