June 2, 2011 (Denver, Colorado) — Resistance training reduces symptoms of generalized anxiety disorder (GAD), compared with aerobic exercise or no exercise at all, according to research presented here at the American College of Sports Medicine 58th Annual Meeting.
Patients with GAD tend to be physically inactive, although exercise training has been shown to reduce anxiety symptoms in healthy adults and patients with chronic disease, and to benefit patients with major depressive disorder.
To investigate the potential benefits of exercise on worry symptoms and anxiety remission rates in patients with GAD, researchers randomized a group of 30 sedentary women with a primary DSM-IV diagnosis of GAD to receive a 6-week regimen of either resistance training or aerobic exercise training, or to be placed on a wait list (control group).
The women were not involved in any treatment other than pharmacotherapy.
After the 6-week training period, the researchers found rates of anxiety remission to be as high as 60% in the resistance training group, compared with 40% in the aerobic exercise group and 30% in the control group.
The resistance training consisted of 2 weekly sessions of lower-body weightlifting, starting at 50% of 1 repetition maximum during week 1, and progressing 5% weekly.
The aerobic exercise training involved 2 weekly sessions of leg cycling, matched with resistance training on the body region exercised, and weekly load progression.
Rates of remission were defined as the number needed to treat (NNT). Worry symptoms were measured with the Penn State Worry Questionnaire, and analyzed using a mixed-model condition × time (3 × 3) analysis of covariance, adjusted for a baseline and testing period.
In addition to the improvements in remission rates, an assessment of remission based on NNT showed 3.33 (95% confidence interval [CI], 1.72 to 55.56) for resistance exercise training and 10 (95% CI, –6.79 to 2.88) for aerobic training.
The results also showed a significant condition × time interaction for worry symptoms (F[3.962, 49.529], 2.815; P = .035).
A follow-up contrast showed significant reductions in worry symptoms for combined exercise conditions, compared with the control group (t[25.943], 2.168; P = .039).
The researchers theorized that because depression and GAD are influenced by similar genetic factors, anxiety might show improvement from exercise similar to that seen with depression.
They also noted that there were exercise effects on other signs and symptoms of GAD, including fatigue, poor concentration, and muscle tension.
Lead author Matthew P. Herring, PhD, a postdoctoral fellow in the Department of Exercise Science at the University of South Carolina, Columbia, speculated that the greater improvement with resistance exercise might be related to the intensity of the activity.
“Findings of lower rates of remission for aerobic exercise suggest that the effect of exercise was plausibly related to the relative exercise intensity, as indicated by ratings of perceived exertion during each exercise session,” he explained. “Aerobic exercise sessions were perceived as less intense than resistance exercise sessions.”
He added that the study looked primarily at women because they are more frequently affected by GAD than men, and the disparity only increases with age.
“Although functional impairments and comorbid conditions are present for both men and women with GAD, disability and rates of comorbid mood disorders are significantly higher among women.”
“Future research trials should examine potential gender differences in exercise effects among men and women with GAD.”
In the meantime, Dr. Herring said, the findings demonstrate a strong potential role for exercise in helping to treat anxiety.
“Our findings suggest that exercise training is a feasible, safe, and well-tolerated short-term treatment option, potential adjuvant therapy, or augmentation for patients with generalized anxiety disorder,” he asserted. “These findings warrant further investigation with larger trials.”
David B. Coppel, PhD, director of neuropsychological services and research at the Seattle Sports Concussion Program, and professor at the University of Washington, agreed that additional research should look into the effects of exercise in both sexes, but he said the study raises a number of other questions.
“I would particularly like to know the cognitive and emotional shifts made by the subjects and their attributional model. For instance, did it make them feel more effective or participatory in their lives, or just more activated,” Dr. Coppel wondered.
Other questions to look into are whether the results represented an interaction of medication and exercise, how long the effects of exercise last, and what the results are if there are secondary diagnoses, he added.
“The research is interesting and in line with the ‘exercise as medicine’ idea. Certainly the article suggests results that are consistent with other research from mild depression literature,” Dr. Coppel told Medscape Medical News.
The study was supported by a grant from the University of Georgia College of Education in Athens. Dr. Herring and Dr. Coppel have disclosed no relevant financial relationships.
American College of Sports Medicine (ACSM) 58th Annual Meeting: Abstract 601. Presented June 1, 2011.