Sleep in elite swimmers: prevalence of sleepiness, obstructive sleep apnoea and poor sleep quality.

Objectives: Limited data suggest that swimmers might be affected by poor quality of sleep significantly. The aim was to explore the prevalence of sleep disturbances in swimmers and possible link between rhinitis and sleep disturbance.

Methods: Study 1 was an observational case-control, questionnaire-based study involving 157 elite and non-elite swimmers, 36 non-swimming athletes and 50 controls. In study 2, we measured sleep quality and duration using actigraphy in 20 elite swimmers. We also looked for presence of sleep-disordered breathing using overnight pulse oximetry monitor.

Results: In study 1, we observed a significant difference in prevalence of excessive daytime sleepiness between groups of elite swimmers and controls. Pittsburgh Sleep Quality Index (PSQI) scores do not suggest that quality of sleep in group of swimmers is impaired. In study 2, we found that prevalence of obstructive sleep apnoea (OSA) in elite swimmers defined as oxygen desaturation index ≥5 was 30%. Analysis of actigraphy data revealed that on nights prior to training days, 'going to' bed time was significantly earlier and total sleep time was significantly reduced.

Conclusion: Swimmers and non-swimming athletes suffer significantly more with excessive daytime sleepiness than healthy controls. In elite swimmers, this is likely linked to high prevalence of OSA. PSQI scores do not suggest that quality of sleep in group of swimmers is impaired, but actigraphy shows great variations between sleep pattern preceding training and rest day. This seems to be associated with early-morning sessions which can be a disruptive element of weekly sleep patterns.