Now a new study has found a difference in the way women's bodies work which could affect sleep. Apparently, the circadian rhythm runs faster in women which may account for why women tend to wake earlier than men and why women are more likely to suffer from sleep maintenance insomnia.
The study found that the circadian cycle of women was six minutes shorter on average than that of men. It also found that women were two and a half times more likely to have circadian cycles that ran for less than 24 hours.
Researchers don't know why women appear to have shorter circadian rhythms than men, although it has been suggested that estrogen may be the culprit.
Last updated: June 20, 2011