Non-randomised trial, 1999
Does your menstrual cycle phase affect how alert and focused you stay during sleep deprivation?
Yes, women in the follicular phase were less alert and performed worse on thinking tasks during sleep deprivation, especially at times when body temperature naturally dips. This is a small study without a comparison group.
What they did
25 healthy young women stayed awake for 24 hours while researchers measured alertness, thinking ability, and body rhythms at different menstrual cycle phases using a controlled procedure.
What they found
Alertness and cognitive performance worsened during sleep deprivation and were poorest in the follicular phase, especially near the body temperature low point. Melatonin levels did not differ between cycle phases, but oral contraceptive use increased melatonin levels. Body temperature was higher in the luteal phase and in women taking oral contraceptives.
What it means for you
Hormonal changes from your cycle affect how tired you feel during sleep loss, but do not change when your body's natural 24-hour rhythm peaks and dips. The main limitation is the small sample size and lack of a comparison group.
25
women studied
24 hours
sleep deprivation duration
follicular phase
when alertness was poorest
About the study
- Original title
- Effects of menstrual cycle phase and oral contraceptives on alertness, cognitive performance, and circadian rhythms during sleep deprivation
- Authors
- Wright KP Jr, Badia P
- Journal
- Behavioural brain research
- Year
- 1999
- Study design
- Non-randomised trial
- Participants
- 25
- What was tested
- None - comparison of menstrual cycle phases
- Read the paper
- doi.org/10.1016/s0166-4328(99)00042-x
Topics
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