Resistance exercise training compared to a low-intensity sham for depressive symptoms in young women with analogue generalized anxiety disorder: A randomized controlled trial

This randomized controlled trial (RCT) quantified the effects of resistance exercise training (RET)compared to low-intensity sham RET attention-control (SHAM) on depressive symptoms among young women (18-40y) with analogue Generalized Anxiety Disorder (AGAD). Methods: Fifty-five participants (21.8 ± 2.2y) with AGAD (Psychiatric Diagnostic Screening Questionnaire GAD subscale (≥6) and Penn State Worry Questionnaire (≥45)) were randomized to eight weeks of World Health Organization and American College of Sports Medicine guidelines-based, progressive, moderate-to-high-intensity (70–80% one-repetition maximum (1RM)) RET (PRET) with two sets of 8–12 repetitions of eight exercises, or a SHAM (20% 1RM), both preceded by a two-week familiarization. The 16-item Quick Inventory of Depressive Symptomatology (QIDS) measured depressive symptoms at baseline, post familiarization, week four, eight, and one-month follow-up. A two (group) by five (time-point) repeated measures ANOVA quantified differences between groups. Standardized mean difference (SMD) quantified the magnitude of within-condition change. Hedges' d effect sizes quantified the magnitude of difference in change between groups. Results: No significant group by time interaction was found for depressive symptoms (F(3.2167) = 0.34, p = 0.806; d = 0.17[95%CI: 􀀀 0.36 to 0.70]). A significant main effect for time was found (F(3.2167) = 42.19, p < 0.001); PRET (SMD = 1.53[95%CI: 0.92 to 2.13]) and SHAM (SMD = 1.04[95%CI: 0.49 to 1.60]) induced large magnitude reductions in depressive symptoms, that were maintained (SMD: PRET: 1.64[95%CI: 1.02 to 2.26]; SHAM: 1.15[95%CI: 0.59 to 1.72]) at one-month follow-up. Conclusion: PRET and low-intensity RET can induce large antidepressant benefits. Although the difference between PRET and SHAM was unconfirmed, larger within-condition effects indicate greater benefits of PRET; however, benefits can also occur following lower-intensity RET.