Researchers have found that low-intensity exercise triggers brain networks involved in cognition control and attention processing, while high-intensity exercise primarily activates networks involved in emotion processing.
Using resting state functional magnetic resonance imaging (Rs-fMRI), a noninvasive technique that allows for studies on brain connectivity, the study, published in the journal Brain Plasticity, shows for the first time that low and high exercise intensities differentially influence brain function.
"We believe that functional neuroimaging will have a major impact for unraveling body-brain interactions," said study lead author Angelika Schmitt from University Hospital Bonn in Germany.
"These novel methods allow us to 'look' directly into the brains of a group of athletes, and, maybe even more importantly, understand the dynamic changes in brain structure and function associated with the transition from a sedentary to a healthy lifestyle," Schmitt added.
For the findings, 25 male athletes underwent individual assessments using an incremental treadmill test.
On separate days they performed low and high-intensity exercise bouts for 30 minutes.
Before and after exercising, Rs-fMRI was used to examine functional connectivity of different brain regions that are linked to specific behavioural processes.
Participants also completed a questionnaire to measure positive and negative mood before and after the exercise.
The behavioural data showed a significant increase in positive mood after both exercise intensities and no significant change in negative mood.
The results of the Rs-fMRI tests showed that low-intensity exercise led to increased functional connectivity in networks associated with cognitive processing and attention.
High-intensity exercise, on the other hand, led to increased functional connectivity in networks related to affective, emotional processes.
According to the researchers, high-intensity exercise also led to a decreased functional connectivity in networks associated with motor function.
The investigators noted that this is the first study to report distinct effects of exercise intensity on specific functional networks within the brain at rest.