How Does Yoga Reduce Stress?, A Clinical Trial Testing Psychological Mechanisms Author: Crystal L Park1, Lucy Finkelstein-Fox1, Shane J Sacco2, Tosca D Braun3, Sara Lazar4 Affiliation: <sup>1</sup> Department of Psychological Sciences, University of Connecticut. <sup>2</sup> Department of Allied Health Sciences, University of Connecticut. <sup>3</sup> Warren Alpert Medical School of Brown University. <sup>4</sup> Department of Psychiatry, Massachusetts General Hospital. Conference/Journal: Stress Health Date published: 2020 Aug 14 Other: Special Notes: doi: 10.1002/smi.2977. , Word Count: 213 Yoga interventions can reduce stress, but the mechanisms underlying that stress reduction remain largely unidentified. Understanding how yoga works is essential to optimizing interventions. The present study tested five potential psychosocial mechanisms (increased mindfulness, interoceptive awareness, spiritual well-being, self-compassion, and self-control) that have been proposed to explain yoga's impact on stress. Forty-two participants (62% female; 64% White) in a yoga program for stress reduction completed surveys at baseline (T1), mid-intervention (T2), and post-intervention (12 weeks; T3). We measured two aspects of stress, perceived stress and stress reactivity. Changes were assessed with paired t-tests; associations between changes in mechanisms were tested in residual change models. Only stress reactivity decreased, on average, from T1 to T3. Except for self-compassion, all psychosocial mechanisms increased from T1 to T3, with minimal changes from T2 to T3. Except for self-control, increases in each mechanism were strongly associated with decreases in both measures of stress between T1 and T2 and decreases in perceived stress from T1 to T3 (all p's<.05). Increased psychosocial resources are associated with stress reduction. Yoga interventions targeting these resources may show stronger stress reduction effects. Future research should test these linkages more rigorously using active comparison groups and larger samples. This article is protected by copyright. All rights reserved. Keywords: Yoga; mind-body; self-regulation; stress-reduction. PMID: 32797683 DOI: 10.1002/smi.2977