Associations between expectations and responses to chronic resistance exercise in young adults with and without analogue generalized anxiety disorder.

Chronic resistance exercise training (RET) is largely understudied as a treatment intervention for anxiety disorders. Expectations may play a role in the effect of RET on anxiety and mood responses. Exploring placebo effects in chronic interventions is imperative to understanding the influence of expectations on psychological responses to chronic RET. This study quantified the associations between expectations of psychological outcomes of exercise (EPOE) and observed anxiety symptom and mood state responses to chronic RET among young adults with and without Analogue Generalized Anxiety Disorder (AGAD). An eight-week RET intervention was implemented among 54 young adults (25.8 ± 5y). 26 were randomized to the intervention group and 28 to waitlist (WL). Anxiety symptoms and mood state responses were measured pre and post RET and EPOE were measured at baseline. Spearman's rho quantified associations between baseline expectations and anxiety and mood responses. There were no significant associations in the RET sample between EPOE and experienced psychological responses (all rho= -0.41 to -0.07, all p > 0.005). Preliminary findings suggest that the mental health benefits of chronic RET were independent of placebo effects, notwithstanding the potential limitations of small sample size and the non-mode-specific measure of expectations. Future research should explore the associations of mode-specific EPOE in larger sample sizes.