In a recent study published in the journal Progress in Cardiovascular Diseases, researchers explore whether exercise could be used to treat anxiety.

Study: Is exercise a viable therapy for anxiety? Systematic review of recent literature and critical analysis. Image Credit: GP PIXSTOCK / Shutterstock.com

The mental health benefits of exercise

Lifestyle psychiatry acknowledges the impact of various health behaviors, such as nutrition, sleep, smoking, and physical activity on mental health.

Physical exercise is a well-known health behavior that provides both physical and psychological benefits. In fact, exercise is now recommended as the primary treatment for mild to moderate depression and as an adjunctive treatment for severe mental illness. However, the impact of exercise on anxiety has not been studied as extensively as its effect on depression.

About the study

The current review included studies that evaluated the impact of long-term exercise on anxiety outcomes in people with anxiety disorders or high levels of anxiety symptoms. To this end, a systematic search was conducted in April 2022 on MEDLINE, EMBASE, CINAHL, and PsycINFO for peer-reviewed studies in English. The selected studies obtained measurements from participants for anxiety-related disorder symptoms or elevated symptoms of anxiety.

Only randomized clinical trials (RCTs) that fulfilled specified criteria were included in the review. These included articles published in English in a peer-reviewed journal, articles published between January 2014 and December 2021, eligible participants were at least 18 years old, at least 30 participants were included in the study, exercise interventions included more than one round of resistance training or aerobic exercise, the primary outcome measure was anxiety, and elevated anxiety symptoms were estimated using a validated assessment instrument or diagnosed using an established procedure like a psychiatric interview.

In addition to the inclusion criteria, any selected study provided information on the control condition, exercise intervention, participant demographics, percent attrition, primary outcome, anxiety measures, and anxiety-related results, including an objective to determine if exercise contributed to reduced anxiety.

Unclear impact of exercise on anxiety

A total of 7,240 records were identified during the electronic database search; however, after removing 1,952 duplicate entries, 5,288 unique articles remained.

Of these, 98.7% were excluded after the title and abstract were reviewed. Finally, the review examined 70 studies and 25 RCTs that met the eligibility criteria.

Nineteen of these studies relied on self-report questionnaires to assess anxiety levels before the intervention. These questionnaires included the Spielberger State-Trait Anxiety Scale (STAI), Beck Anxiety Inventory (BAI), anxiety subscale of the Hospital Anxiety and Depression Scale (HADS), Anxiety Sensitivity Index (ASI), Psychiatric Diagnostic Screening Questionnaire (PDSQ), and Posttraumatic Stress Disorder (PTSD) Checklist (PCL).

Baseline anxiety was evaluated in four studies using structured interviews such as the Clinician-Administered PTSD Scale (CAPS), Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders (DSM), and Hamilton Anxiety Rating Scale (HAM-A).

Seven provided conclusive evidence that exercise intervention groups experienced improvements in their disorder status or anxiety symptoms as compared to controls. In two of the 13 studies conducted on anxious individuals, no clear reductions in anxiety levels were observed for the exercise cohort as compared to controls.

Six studies reported insignificant or no variations in anxiety levels between those who exercised and those who did not. In 12 studies, including eight trials involving anxious individuals, the findings were considered inconclusive or equivocal. Most of the studies yielded mixed results, as a reduction in anxiety was observed for certain measures or assessment periods.

Three studies reported positive findings; however, due to significant methodological limitations, it was difficult to determine whether exercise equivocally reduced anxiety. Moreover, four studies analyzed potential mediators or moderators of the anxiety-exercise correlation.

Three studies found that the level of anxiety reduction due to exercise was influenced by the number of exercise sessions attended or the initial level of anxiety. Specifically, attending more exercise sessions was related to greater anxiety reduction, while higher baseline anxiety levels were also related to greater anxiety reduction.

Two studies examined potential mediators, including participants’ daily steps and increased aerobic fitness levels; however, these analyses did not produce a significant outcome.

Conclusions

The limited number of reliable studies and absence of positive results in over half of the reviewed studies limit the ability to draw definite conclusions about the effectiveness of exercise as a treatment for anxiety in patients.

Further research is needed to determine the advantages of exercise for people with anxiety. Clinicians who recommend exercise as therapy for anxiety must prioritize patient safety, establish clear and achievable exercise goals, and closely monitor symptoms.