Study, 1999
Does how sleepy women feel change at different times of day during the menstrual cycle?
Yes. During daytime hours, women feel more sleepy and have more deep sleep during naps in the second half of the cycle, but sleepiness does not differ at other times of day.
What they did
Healthy women participated in an ultra-short sleep-wake schedule study measuring their 24-hour sleep patterns during the first half (follicular) and second half (luteal) of their menstrual cycle.
What they found
During daytime hours (09:00 to 16:30), subjective sleepiness and the number of deep sleep-containing nap trials increased in the luteal phase compared to the follicular phase. The mean overall sleep propensity did not change. During evening and night hours (17:00-00:30 and 01:00-08:30), there were no differences between the two phases.
What it means for you
Increased daytime sleepiness in the luteal phase may be related to how the brain controls deep sleep. The study was small and only included healthy women, with no separate control group mentioned.
About the study
- Original title
- Diurnal fluctuation of sleep propensity across the menstrual cycle
- Authors
- Shibui K, Uchiyama M, Okawa M et al.
- Journal
- Psychiatry and clinical neurosciences
- Year
- 1999
- Study design
- Study
- Open access
- Yes
- Read the paper
- doi.org/10.1046/j.1440-1819.1999.00489.x