The Roles of Physical Activity, Exercise, and Fitness in Promoting Resilience During Adolescence: Effects on Mental Well-Being and Brain Development

Abstract

Adolescence is a critical yet vulnerable period for developing behaviors important for mental well-being. The existing literature suggests that physical activity (PA), exercise, and aerobic fitness promote well-being and reduce risk of mental health problems. In this review, we focus on PA, exercise, and fitness as modifiable resilience factors that may help promote self-regulation via strengthening of top-down control of bottom-up processes in the brain, thereby acting as a buffer against mental health problems during this period of vulnerability. First, we briefly review the link between PA, exercise, and aerobic fitness with mental well-being and reduced mental health problems in adolescence. Then we present how impairments in self-regulation, which involves top-down control to modulate bottom-up processes, are common across a wide range of mental health disorders. Finally, we use the extant neuroimaging literature to highlight how neural systems underlying top-down control continue to develop across adolescence, and propose that PA, exercise, and aerobic fitness may facilitate resilience through strengthening individual brain regions as well as large-scale neural circuits to improve emotional and behavioral regulation. Future neuroimaging studies assessing the effects of PA, exercise, and aerobic fitness at various developmental stages in each sex and studies considering the characteristics (e.g., frequency, intensity, type) and social context of PA and exercise are vital to better understand both macro- and microscale mechanisms by which these behaviors and attributes may facilitate mental health resilience during adolescent development.

Keywords: Emotion; Externalizing symptoms; Internalizing symptoms; Neurodevelopment; Prefrontal cortex; Self-regulation.

Figure 1.

A) Schematic of the prefrontal cortex’s role involved in emotional and behavioral self-regulation through top-down (dashed circles) and bottom-up (solid circles) processes and B) Brain regions involved in top-down and bottom-up processing interact with other brain regions as part of large-scale networks, such as the corticolimbic (green), frontoparietal (yellow), and the default mode (red) networks to generate complex thoughts and behaviors. Abbreviations: LPFC: lateral prefrontal cortex; mPFC: medial prefrontal cortex; ACC: anterior cingulate cortex; AMY: amygdala; HIP: hippocampus; VS: ventral striatum; IPS: intraparietal sulcus; TPJ: temporoparietal junction; PCC: posterior cingulate cortex; OFC: orbitofrontal cortex

Figure 2.

Schematic of emotional, neurodevelopment, and physical activity changes that occur simultaneously across adolescence. A) Prevalence of behavioral problems and internalizing disorders emerge with age across adolescence (based on data from the 2018 National Survey of Children’s Health (149)). B) Regional and network specific changes occur in structural and functional brain maturation, including decreases in cortical thickness (red to blue), increases in white matter development (bundle thickness), and refinement of functional brain networks (circles, lines). C) Meanwhile, moderate to vigorous physical activity levels significantly decline as children transition into adolescence (based on data from the 2003–2006 National Health and Nutrition Examination Survey (69)). Images were created using the QIT software package (150).

Figure 3.

Theoretical model as to how PA/exercise and fitness impacts brain structure and function to promote resilience against mental health problems during adolescence. MRI studies in children and adolescence have shown PA/exercise and fitness relate to white matter fiber tracts (blue) and morphometric and brain activity differences in specific brain regions (dashed lines). We hypothesize that these structural and functional differences occurring with PA and exercise (to enhance fitness) may contribute to resilience against mental health problems through facilitating the integration of top-down control of bottom-up processes within the large-scale corticolimbic (green), frontoparietal (yellow), and default mode (red) networks to enhance behavior and emotional self-regulation during adolescent development. Abbreviations: CC: corpus callosum; SLF: superior longitudinal fasciculus; CST: corticospinal tract; UNC: uncinate fasciculus; PFC: prefrontal cortex; LPFC: lateral prefrontal cortex; vmPFC: ventromedial prefrontal cortex; dACC: dorsal anterior cingulate cortex; AMY: amygdala; HIP: hippocampus; VS: ventral striatum; IPS: intraparietal sulcus; TPJ: temporoparietal junction; PCC: posterior cingulate cortex; OFC: orbitofrontal cortex