Running Away From Depression with Your Brain and Your Heart

Physical activity is associated with beneficial effects on various indicators of physical and mental health. Especially in times of the current global pandemic, the manifold benefits of being physically active are widely acknowledged. Recent neuroscience findings revealed that already two weeks of regular, moderately intense running result in a significant reduction of symptoms related to depression, along with significant increases in the volume of the hippocampus a brain region that is critically implicated in depression. What is not clear in the literature is whether these changes are shaped by biological or social mechanisms, or by a combination of both. Given that many physical activity interventions are performed in groups, it may well be the case that social mechanisms, in addition to biological factors, are the drivers of the effect. The current project addresses the central research question of whether the beneficial effects of running on brain and affective functions are driven by social or biological mechanisms or by a combination of both. To this end, two running intervention groups will be investigated, the one running individually, and the other one running in small groups of people. All participants will run on the very same running route in a mostly forested recreational area over a time period of several weeks. The study design will involve several time points of assessment (involving magnetic resonance imaging, MRI; psychometric assessments; and electrocardiography, ECG) to address the exciting research question of whether any intervention effects remain stable over time or return to baseline after periods of no exercise, or as an important extension to literature whether the effects further increase as a result of continued training. The assessment of intervention effects will involve affective (e.g., symptoms related to depression, perceived stress) and cognitive functions (e.g., creativity). The assessment of parameters of the ECG (heart rate and heart rate variability) will provide important information on changes of stress- related psychophysiological factors and indicators of physical and/or mental fitness following regular running. Taken together, this project is designed to replicate and to extend previous research, especially concerning issues related to dose and response, the continuous assessment of functional and structural characteristics of the brain, and regarding potential mechanisms (social and/or biological) underlying the effects. In addition, established parameters of the ECG provide important biomarkers to assess changes in psychophysiological stress-related functions following regular running. Given that randomized controlled longitudinal intervention studies, especially in samples involving young adults from the general population are rare, the findings of this study add important new evidence on the role of aerobic exercise in cognitive, affective, and brain functions.