Buff arms and tight abs aren’t the only benefits of resistance training. There’s growing evidence that it may help you resist excessive worry and anxiety, too.
Resistance training (aka strength training or weight training) builds muscular strength and endurance by exercising a muscle or muscle group against external resistance. Free weights, dumbbells, weight machines, resistance bands, medicine balls, or the weight of your own body can be used to challenge your muscles this way.
In the process, you might be doing your mental outlook a favor, too. “The research literature suggests that even single bouts of resistance exercise may produce moderate improvements in anxiety,” says Justin Strickland, M.S., a doctoral student at the University of Kentucky and lead author of a journal article reviewing this research.
Likewise, Strickland notes, several small studies have found reductions in anxiety when resistance training is done regularly for six weeks or longer. That holds true across a range of study populations, including older adults, stroke survivors, and women with polycystic ovary syndrome.
A mountain of evidence shows that aerobic exercise—such as brisk walking, running, cycling, or playing tennis—can help improve your mood, reduce your stress, and boost well-being. Comparatively speaking, research on the anxiety-fighting potential of resistance training is still at the molehill stage. Although there’s a lot yet to be learned, early studies offer clues to how resistance exercise may help keep anxiety at bay.
Worrying now and then is part of life. But for people with generalized anxiety disorder (GAD), excessive, ongoing worry and anxiety about a variety of things can spiral out of control. Disturbed sleep often goes hand in hand with this pattern of chronic worrying. People with GAD may have trouble falling asleep, or their slumber may be fitful and restless.
One way resistance training might be beneficial is by promoting better sleep. In an interesting study, young women with GAD were randomly assigned to lower-body weight training (resistance exercise), cycling (aerobic exercise), or a waiting list (the control group). The resistance and aerobic exercise groups each worked out twice a week for six weeks.
Both types of exercise improved sleep, especially on the weekend. Resistance training was particularly helpful. “Basically, short-term exercise training helped these young women go to sleep more quickly and sleep more efficiently,” says Matthew Herring, Ph.D., the lead researcher and a lecturer in exercise psychology at the University of Limerick in Ireland. Improvements in sleep were associated with reductions in anxiety.
“Our findings did not really address whether reduced anxiety led to better sleep, or vice versa,” Herring says. However, other research suggests that the relationship cuts both ways, and physical activity may be good for both at the same time.
A second way in which resistance training may be beneficial is by reducing anxiety sensitivity—fear of the physical sensations caused by anxiety. People who are high in anxiety sensitivity often catastrophize such sensations, says Joshua Broman-Fulks, Ph.D., a professor of clinical psychology at Appalachian State University.
For instance, they might believe that an anxiously racing heart is a sign of an impending heart attack. That only makes them feel even more alarmed. Over time, they begin to fear not only the object or situation that originally set off their anxiety, but also the distressing sensation itself.
In a study headed up by Broman-Fulks, volunteers were randomly assigned to a single, 20-minute session of weight training (resistance exercise), treadmill use (aerobic exercise), or rest (the control group). Afterward, they took part in a carbon dioxide challenge task. This involved inhaling a whiff of carbon dioxide mixed with oxygen, which made them feel momentarily breathless—a sensation that mimicked the rapid, shallow breathing caused by anxiety. They also responded to a questionnaire that measured anxiety sensitivity.
The results showed that resistance exercise and aerobic exercise were equally effective at reducing anxiety sensitivity. The study didn’t look at how exercise exerted this effect, but Broman-Fulks speculates that it may “serve as a form of exposure therapy to feared sensations among individuals with high anxiety sensitivity.”
Exposure therapy is a well-established treatment for anxiety. In this approach, people systematically confront a situation that frightens them excessively. As they see that they can face the situation without anything terrible happening, their fear starts to fade away.
For volunteers in the study, moderate-intensity exercise allowed them to confront the sensation of breathing a little harder than normal. In the lab, that experience seemed to help them cope with the carbon dioxide challenge that followed. Out in the world, positive exercise experiences may help people notice breathlessness due to anxiety without overreacting to it.
Along with changes in breathing, other physiological responses to exercise include an elevated heart rate and increased sweating. Although we often associate these changes with aerobic workouts, Broman-Fulks notes that strength work can bring them on, too.
“During resistance training, brief periods of rest between sets allow those sensations to normalize a bit before being increased again with the next set,” he says. He likens the effect to conducting numerous "mini-exposure sessions" with every resistance training workout.
“In our study, a single bout of resistance training led to significant reductions in anxiety sensitivity,” says Broman-Fulks. “The cumulative evidence to date suggests that weight training may be an effective way to reduce anxiety and other negative mood states.”
Broman-Fulks, J. J., Kelso, K., & Zawilinski, L. (2015). Effects of a single bout of aerobic exercise versus resistance training on cognitive vulnerabilities for anxiety disorders. Cognitive Behaviour Therapy, 44, 240-251.
Herring, M. P., Kline, C. E., & O’Connor, P. J. (2015). Effects of exercise on sleep among young women with generalized anxiety disorder. Mental Health and Physical Activity, 9, 59-66.
Strickland, J. C., & Smith, M. A. (2014). The anxiolytic effects of resistance exercise. Frontiers in Psychology, 5, 753.