Sleep disorders and exercise: a mini-review.

Sleep disturbance in a growing problem in the general population. As the prevalence of sleep disturbance rises, interest in treatment modalities including non-pharmaceutical interventions also grows. One of these potential modalities is exercise therapy. In individuals without sleep disorders, exercise appears to be beneficial in improving sleep architecture without any impact of the timing of exercise in relation to onset of sleep. The mechanisms for this are largely unknown but may be due to a combination of the effects of exercise on body temperature, autonomic control, endocrine and metabolic function. In obstructive sleep apnoea (OSA), supervised exercise therapy appears to have positive impact on daytime sleepiness with an unknown impact on sleep quality. The effect of exercise on central sleep apnoea (CSA) will be difficult to ascertain due to the low prevalence of this condition. In primary sleep disorders such as insomnia, narcolepsy and restless syndrome exercise may be useful in improving sleep architecture but the quality of the evidence supporting this remains low. In addition, the timing of exercise in relation to sleep onset remains under investigated. In individuals with circadian rhythm disorders, evening exercise appears to delay sleep onset. In shift-pattern workers, individuals with increased cardiorespiratory fitness report better sleep quality, suggesting exercise may be protective in this important population. To allow high quality evidence-based recommendations to be made about the value of exercise in individuals with sleep disorders, there is a significant need for large prospective studies with objective and subjective sleep quality as a primary outcome.