Figure 1.

Evidence-based mechanisms (only those confirmed by RCTs) of exercise that contribute to its salutary effects on cognition. Evidence is presented across three different levels of analysis and separated by age group to highlight emerging patterns and existing gaps in evidence. While there are complexities in defining specific age ranges for developmental periods such as adolescence, age group is used to simplify the presentation of the studies discussed here. Level 1 refers to cellular and molecular signaling pathways. Level 2 refers to brain structural or functional pathways, and Level 3 refers to psychosocial pathways which are defined as higher-order behaviors or mental states.