Chronic exercise training has a unique influence on sleep in female athletes

Sleep is essential in sustaining human life. Researchers at University of Tsukuba found that, for female athletes, differences in daily training and reproductive function produced different phenomena in sleep stages and energy expenditure during sleep, all of which may be related to the deep sleep stage (slow-wave sleep [SWS]). Their study is published in the journal iScience.

In particular, the presence and absence of menstruation and the menstrual cycle revealed different patterns of energy expenditure during sleep and fluctuations in the sleep stages. Furthermore, phenomena occurring in menstrual cycles among athletes with chronic exercise training differed from those among general women without training.

For female runners, the sleeping metabolic rate and SWS were higher in the luteal than in the follicular phase. These findings suggest that the phenomena occurring in energy expenditure during sleep and the sleep stages vary depending on the extent of reproductive function differences and the presence or absence of chronic exercise training.

In this study, the researchers focused on energy metabolism to clarify the complex relationships of factors such as chronic exercise training, menstruation presence or absence, menstrual cycle, and sex on sleep. Further research on the mechanisms underlying these differences may aid in the development of preventive measures and solutions for amenorrhea among female athletes.