A Systematic Review of the Mediators of Resistance Training Behavior.

Background: Resistance training (RT) has been identified as an important lifestyle activity for health. While systematic reviews have examined behavior change techniques (BCTs) used in interventions and potential correlates of RT behavior, the connection between BCTs and changes in putative mediators and RT participation have yet to be linked. The purpose of this review was to examine RT intervention effects, as coded by BCT clusters, on behavior change via capability, opportunity, and motivation as putative mediators of that change.

Method: Literature searches were concluded in January of 2023, using three databases. Eligible studies included a comparison group, assessed RT as an outcome, included BCTs, assessed potential mediators, and were in English. The initial search yielded 1050 hits, which was reduced to 5 to independent RT interventions. Screening of previous reviews yielded three additional papers for a total of 8 papers. Each paper was assessed for the associations between intervention effects (as BCT clusters) on mechanisms of action (a path), effects of mechanisms of action on behavior (b path), and indirect (ab path) and direct (c path) effects of BCT clusters.

Results: There was support that interventions had significant effects on capability and opportunity with inconclusive effects on motivation (a path). Both capabilities and motivation had associations with RT behavior (b path). The examined studies showed that changes in capabilities have the strongest support as a mediator with some support for motivation as a mediator (ab path). Studies that used more BCT clusters seemed to have a more positive effect on behavior, yet there were no trends to suggest any one crucial BCT cluster (c path).

Conclusion: Current evidence suggests that capabilities and motivation are important to target in RT interventions. Future interventions would be well suited to utilize behavior change techniques that address these mediators.