Relationship to the research frontline In contrast to the literature on depression there are very few clinical studies on physical exercise as an intervention for anxiety. All six trials performed hitherto were identified as being at a high risk of bias. Higher quality trials are thus required. There is a need to investigate the role of intensity, volume, frequency and type of exercise on anxiety symptoms, cognitive function and working ability in people with anxiety disorders. Also, the putative mechanisms behind the potential effects on anxiety symptoms are not elucidated and deserve attention.