Brain resting state functional connectivity changes with aerobic exercise, and mindfulness: A narrative review

Neuroimaging studies show that the functional connectivity of the brain changes with age. Resting state functional connectivity (rsFC) in the brain appears to decrease with aging in key networks associated with higher order thinking and effective emotional regulation. Interventions that potentially preserversFC in the brain include 1) physical activity and 2) contemplative practice commonly referred to as mindfulness. The present narrative review aims to summarize the literature concerning the effect of interventions involving exercise, mindful movement, and purely mindfulness-based training on rsFC. Search terms focused on identifying multi-day exercise, mindfulness, or mindful-movement interventions in non-clinical adult populations that included a control group and both pre- and post-assessment of brain rsFC. Thirty studies were reviewed. Assessed methodological factors that potentially impact findings included subject sample size, scan time length, brain regions targeted for analyses, intervention length and intensity , population characteristics, and differences in sleep quantity/quality. Most studies reported changes in rsFC related to interventions with most observed changes found within the default mode, executive control and salience networks of the brain. However, the largest and most methodologically rigorous study found minimal associations between rsFC and either exercise or mindfulness. Given the inconsistent results found in this review, caution is warranted in the interpretation of changes in rsFC attributable to exercise and mindfulness. This review highlights key factors likely to contribute to differences in reported outcomes. Methodological consistency in fMRI acquisition, data preparation, and analytical approaches are crucial to improve reproducibility and allow for comparison and aggregation.