A recent meta-analysis of 66 studies reported small to moderate effects on the positive benefit of both acute and regular exercise on sleep disturbance in non-clinical populations, suggesting that it may be useful to further investigate whether this positive benefit of regular exercise on sleep would also exist in clinical populations (e.g., mood disorders) [61] Most importantly, effect sizes for improvement in insomnia in this study were comparable between those who engaged in regular exercise and those taking pharmacological and receiving psychological interventions for insomnia. A study on resistance and aerobic exercise training in women with generalized anxiety disorder (often comorbid with primary mood disorders) found that participants reported improved sleep initiation and continuation after six weeks. Furthermore, there was a significant relationship between generalized anxiety disorder clinical severity rating scores and sleep efficiency [62]. Given these preliminary findings on the benefits of exercise for sleep in anxiety disorders and insomnia, exercise may also be beneficial for sleep disturbance in mood disorders given the high rates of comorbid anxiety [4, 63–66]. However, few rigorous studies have investigated the impact of exercise on sleep in psychiatric populations, and, thus, this requires further investigation.
