A single bout of exercise can sharpen thinking. But does everyone’s brain respond in the same way? Probably not. The lifestyles of those who participate in exercise sessions will likely differ from person to person. Some spend much of their day sitting, while others accumulate considerably more light and moderate-to-vigorous physical activity. We wondered whether these habitual movement patterns might influence how much cognitive benefit someone receives from an acute bout of exercise.
This question matters because exercise does not occur in isolation. Every single day contains 1,440 minutes, divided among sleep, sedentary behavior and physical activity of different intensities. Changing time in one behavior inevitably changes time available for another. Yet research has traditionally focused on the exercise bout itself, paying much less attention to the behavioral context in which that exercise occurs.
In our study, published in Medicine & Science in Sports & Exercise®, 68 healthy young adults wore accelerometers for seven days so that we could objectively characterize how they distributed lifestyle behaviors across the day. Participants then completed a 10-minute bout of moderate-intensity cycling. Before and after exercise, we measured executive function and assessed brain responses using functional near-infrared spectroscopy and transcranial magnetic stimulation.
As expected, exercise helped. Participants generally performed better on executive-function tasks following just 10 minutes of cycling. But when we looked more closely at the accelerometry data, an intriguing pattern emerged. Participants who spent a greater proportion of their day in light and moderate-to-vigorous physical activity showed larger improvements in working memory after exercise. In contrast, greater relative sedentary time was associated with weaker post-exercise connectivity between regions of the prefrontal cortex involved in executive control.
We also identified naturally occurring sedentary, balanced, and active movement profiles. More active participants already demonstrated better executive function before exercising, particularly when the cognitive task became demanding. Following exercise, the active group also showed increased activation within a prefrontal region involved in working memory. However, the cognitive benefits of exercise were not exclusive to active individuals, that is, executive performance improved across all movement profiles.
This distinction is important. Our findings do not suggest that people must already be active before exercise can benefit their brain. Rather, they raise the possibility that habitual physical activity helps establish a neurocognitive state that is more receptive to an acute exercise stimulus.
This shifts how we might think about exercise and brain health. The question may not simply be, “How much exercise should I do?” It may also be, “How active am I during the rest of my day?”
A workout may provide an immediate cognitive stimulus, but the brain receiving that stimulus has been shaped by the other 23 hours of the day. Perhaps, then, the best way to maximize the cognitive benefits of exercise is not only to exercise, but to build a lifestyle that keeps us moving.
Wei-Peng Teo, PhD, is an associate professor and deputy centre director of the Science of Learning in Education Centre at the National Institute of Education, Nanyang Technological University, Singapore. His research integrates exercise neuroscience, motor control and learning, strength and conditioning, and brain health. His trials investigate high-intensity exercise during inpatient stroke rehabilitation, acute aerobic exercise and neurocognitive function in healthy adults, resistance training and cognition, and motor learning in older adults and people with Parkinson’s disease. Using neuroimaging and non-invasive brain stimulation, he examines how exercise and training influence brain function, neuroplasticity, and performance across aging and clinical populations.
