Associations between sleep and in-race gastrointestinal symptoms: an observational study of running and triathlon race competitors

OBJECTIVE: It remains unstudied whether poor sleep is involved in the etiology of gastrointestinal (GI) problems in athletes. METHODS: Eighty-seven running and triathlon/duathlon race (>60 minutes) participants completed questionnaires to quantify the Sleep Problems Index-(SPI)-I and sleep parameters from the night before races. For GI symptoms, participants reported the severity (0-10 scale) of four upper and three lower symptoms during races. Spearman’s correlations examined whether sleep measures were associated with in-race GI symptoms. Partial correlations were calculated to control for age, resting GI symptoms, and anxiety. RESULTS: SPI-I scores correlated with in-race upper GI symptoms (rho=0.26, p=0.013). Controlling for anxiety attenuated this association (rho=0.17, p=0.117), while other control variables had little effect. Acute sleep quantity and quality were not associated with GI symptoms. CONCLUSIONS: Chronic sleep dysfunction is modestly correlated with in-race upper GI symptoms, though future research should clarify whether this is mediated or moderated by factors like anxiety