Effects of Resistance Exercise on Depressed Mood State: A Randomized Controlled Trial

Purpose This secondary analysis of a randomized controlled trial (RCT) of resistance exercise training (RET) compared to a waitlist quantified the acute effects of a single resistance exercise session on depressed mood state. Methods Sixty-two young adults (26.6 ± 5.6y; 39 female) were randomized to eight weeks of World Health Organization and American College of Sports Medicine guidelines-based RET or a waitlist, with an acute RCT nested in at week one. In the first session, RET participants completed moderate-intensity resistance exercise, comprising two sets of 8-12 repetitions of eight exercises targeting the major muscle groups. Waitlist participants completed 30-minutes of quiet rest. The Depression subscale of the Profile of Mood States Brief Form (POMS-B) measured depressed mood state pre- and 10 minutes post-session. Two group x two time (pre/post) RMANOVAs examined differences between resistance exercise and quiet rest. Sub-analyses were conducted among young adults with analogue Generalized Anxiety Disorder (AGAD), Major Depressive Disorder (AMDD), comorbid AGAD and AMDD, and pre-exercise POMS-B ≥ 1 and ≥ 4. Results No significant group X time interaction (F(1,59) = 1.70, p = 0.198) was found for depressed mood state. Significant main effects for time were found among the total (F(1, 59) = 14.74, p < 0.001), AGAD (F(1, 28) = 13.22, p ≤ 0.001), AMDD (F(1, 12) = 5.12, p ≤ 0.043), POMS-B ≥ 1 (F(1,31) = 30.29, p < 0.001) and ≥ 4 (F(1,11) = 10.71, p = 0.007) samples, such that depressed mood state reduced following a single bout of resistance exercise (d = 0.29 to 1.26) and quiet rest (d = 0.27 to 0.39). Conclusions Resistance exercise and quiet rest elicited significant small-to-large and small-to-moderate magnitude reductions in depressed mood state, respectively, that were not significantly different to each other.