Young adults who participated in a resistance exercise training program saw significant reductions in depressive symptoms, according to a new study published in Psychiatry Research. The study’s results are particularly noteworthy because they indicate that even relatively brief participation in resistance training can lead to noticeable improvements in mood for both men and women.
Traditional treatments for depression, such as antidepressant medications and psychotherapy, have their limitations, including variable efficacy, side effects, and issues related to cost and accessibility. Hence, there exists a compelling need to explore alternative and supplementary treatment options, especially for individuals experiencing mild-to-moderate depressive symptoms.
Prior studies have established the potential antidepressant effects of exercise, but most of these investigations have primarily focused on aerobic exercise training. Resistance exercise training, a less explored avenue in this context, is a form of exercise that involves activities like weight lifting, which aims to increase muscle strength.
“The antidepressant effects of exercise are well-documented, and the majority of interventions have used aerobic exercise,” explained study author Darragh O’Sullivan, a doctoral research student at the University of Limerick. “Previous meta-analytic evidence showed that resistance exercise training also reduces depressive symptoms; however, there is a lack of evidence among young adults. Approximately 37% of cases of depression first develop before the age of 25.”
“Generalized Anxiety Disorder also typically develops in young adulthood, and is highly comorbid with Major Depressive Disorder. Consequently, young adults, particularly those with anxiety, are at-risk for depression. Our lab is currently investigating the suitability of resistance exercise training as an alternative or augmentative treatment for anxiety and depressive symptoms among young adults with and without clinically-meaningful Generalized Anxiety Disorder and Major Depressive Disorder.”
For their new study, the researchers analyzed existing data from two parallel randomized controlled trials. These trials were designed to investigate the effects of resistance exercise training on anxiety symptoms in young adults.
The sample included 55 young adults. To be eligible, participants needed to meet specific criteria, including being aged 18 to 40 years old, having no medical conditions that would contraindicate participation in resistance training, and not being pregnant or lactating.
These participants were randomly assigned to a resistance training program or a wait-list control condition. The resistance training program followed the recommendations from authoritative bodies such as the World Health Organization (WHO) and the American College of Sports Medicine (ACSM). The program comprised eight different exercises, including barbell back squat, barbell bench press, hexagon bar deadlift, seated dumbbell shoulder lateral raise, barbell bent over rows, dumbbell lunges, seated dumbbell curls, and abdominal crunches.
Participants underwent a three-week familiarization process before the official start of the program to ensure they were using the correct lifting techniques and that the resistance levels were appropriate. The twice-weekly exercise sessions were approximately 25 minutes long and were fully supervised by trained personnel.
Participants in the control group did not engage in the resistance training program but completed online questionnaires weekly. They were offered the opportunity to participate in the resistance training program intervention after completing their wait-list condition, but no data were collected during this phase.
Participants attended an average of 83% of the sessions and had an 80% compliance rate, indicating strong engagement with the program. Importantly, there were no adverse events related to the resistance training, demonstrating that it was feasible and well-tolerated.
The researchers found that resistance training significantly reduced depressive symptoms in the total sample of young adults, among both individuals with Major Depressive Disorder and individuals with clinically meaningful symptoms of Generalized Anxiety Disorder. This effect was consistent across both male and female participants.
At baseline, participants had mild depressive symptoms, and the resistance training intervention led to a clinically meaningful reduction in depressive symptoms. The effect size of the reduction was large (d = 1.01), indicating a substantial improvement. The antidepressant effect was most pronounced between weeks one and four.
“Eight weeks of WHO and ACSM-guidelines based resistance exercise training, with two sets of 8-12 repetitions of eight simple exercises, can induce large, clinically-meaningful reductions in depressive symptoms among young adults,” O’Sullivan told PsyPost.
“The antidepressant benefits of engaging with resistance exercise training may plateau after initial improvements, but can continue with further training. Most young adults with at least mild depression can benefit from resistance exercise training; in the current sample, 18 of the 19 participants (95%) that met criteria for at least mild depression at baseline no longer met those criteria by week eight.”
Participants also experienced a significant increase in strength during the intervention. But changes in strength were not significantly associated with changes in depressive symptoms. This suggests that the antidepressant benefits of resistance training may not necessarily depend on increased physical strength but rather on other mechanisms.
“Reductions in anxiety symptoms were also found in the current trial, suggesting that resistance exercise training can simultaneously reduce depressive and anxiety symptoms among young adults with and without clinically-meaningful anxiety,” O’Sullivan noted.
But the study, like all research, has some limitations.
“Resistance exercise sessions were fully supervised, one-on-one, and, consequently, were not fully representative of real-world training, without supervision,” O’Sullivan explained. “Still, extraneous conversation was minimized, and scripted conversation was used, to control for non-exercise benefits of the intervention, including social contact. There was no post-intervention follow-up. Longer-term follow-ups are needed to examine whether depressive symptom reductions are maintained post-intervention.”
The study, “Effects of resistance exercise training on depressive symptoms among young adults: A randomized controlled trial“, was authored by Darragh O’Sullivan, Brett R. Gordon, Mark Lyons, Jacob D. Meyer, and Matthew P. Herring.
