Female Biology Might Play a Role in Sleepless Nights

There are women out there who experience trouble when trying to sleep. However, a new study might help in providing an answer to this problem. According to the new research women might have a tough time when trying to get a good night’s sleep because their circadian (internal body clocks) seems to run at a faster pace compared to men.

The lead author of the study, Dr. Diane Boivin, a professor of psychiatry at McGill University in Montreal, said that the results suggests that women seem to be operating in an ‘internal time zone’ that is different from men. “They go to bed at a later biological time because their clock is shifted earlier, eastward,” said Boivin. The Centre for Study and Treatment of Circadian Rhythms at Douglas Mental Health University Institute in Montreal, an affiliate of McGill, is also directed by Dr. Boivin.

The results from the study showed that the manner females slept throughout the 24-hour circadian day outpaced men. These results could provide an explanation regarding why the sleep-wake cycle in women runs two hours faster compared to men.

According to the National Sleep Foundation, it is more likely for women to report insomnia a few days per week and experiencing daytime sleepiness compared to men. The factor that makes this current study so unique is that researchers were able to control phases of the menstrual cycle and use of hormonal contraceptives in women. The authors of the current research say that sleep differences were seen in women regardless of hormonal changes.

The current study was reported in the Proceedings of the National Academy of Sciences. The research had 15 men and 11 women as participants. All of them shared an average age of being approximately 25 years old.

All of the participants were kept alone in windowless rooms for 36 hours. The researchers were able to control the participant’s exposure to light. They also monitored the changes occurring in their melatonin levels, core body temperature, alertness and sleep.


A ‘cat-nap approach’ was used during the research. It consisted of alternating one-hour waking episodes followed by nap opportunities that were each an hour-long as well. The lights were turned off during sleep and were kept on, but at a very dim setting, when it was time for the participants to wake up.

The results showed that women scored lower with regards to subjective measures of nighttime alertness when compared with men. The authors of the study went on to note that this might aid in explaining why female shift workers experience more fatigue, risk of work-related injury and sleepiness. Though women’s circadian rhythms were different compared to men both sexes shared similar habitual bed and wake times.

The vice president of scientific affairs at the Society for Women’s Health Research in Washington, D.C., Monica Mallampalli said that even though the current study is small it still adds valuable information to the world of science related to sex differences linked to sleep and circadian rhythm.


Jennifer Martin, who is an associate professor at the David Geffen School of Medicine at the University of California, Los Angeles, suggested that women might be predisposed to experiencing insomnia due to their biological circadian phase. Their natural circadian rhythm might also make women more vulnerable to poor sleep, compared to men, when facing similar kinds of stressors.

Martin added that females who face trouble when trying to get a good night sleep should reduce factors in their sleep environment that could play a role in disturbing them. They should stick with a consistent morning rise-time that goes well with their natural wake-up time.

Category: News

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Article by: Douglas Norman

Douglas writes all the latest health news for BodyFatLoss. He is very diligent about finding all the facts and sources of any new health and fitness findings.