The Impact of Physical Activity on Brain Structure and Function in Youth: A Systematic Review

CONTEXT: Advances in neuroimaging techniques have resulted in an exponential increase in the number of studies investigating the effects of physical activity on brain structure and function. Authors of studies have linked physical activity and fitness with brain regions and networks integral to cognitive function and scholastic performance in children and adolescents but findings have not been synthesized. OBJECTIVE: To conduct a systematic review of studies in which the impact of physical activity on brain structure and function in children and adolescents is examined. DATA SOURCES: Six electronic databases (PubMed, PsychINFO, Scopus, Ovid Medline, SportDiscus, and Embase) were systematically searched for experimental studies published between 2002 and March 1, 2019. STUDY SELECTION: Two reviewers independently screened studies for inclusion according to predetermined criteria. DATA EXTRACTION: Two reviewers independently extracted data for key variables and synthesized findings qualitatively. RESULTS: Nine studies were included (task-based functional MRI n = 4, diffusion tensor imaging n = 3, arterial spin labeling n = 1, and resting-state functional MRI n = 1) in which results for 5 distinct and 4 similar study samples aged 8.7 ± 0.6 to 10.2 ± 1.0 years and typically of relatively low socioeconomic status were reported. Effects were reported for 12 regions, including frontal lobe (n = 3), parietal lobe (n = 3), anterior cingulate cortex (n = 2), hippocampus (n = 1), and several white matter tracts and functional networks. LIMITATIONS: Findings need to be interpreted with caution as quantitative syntheses were not possible because of study heterogeneity. CONCLUSIONS: There is evidence from randomized controlled trials that participation in physical activity may modify white matter integrity and activation of regions key to cognitive processes. Additional larger hypothesis-driven studies are needed to replicate findings.