An extra hour of sleep 'boosts women's likelihood of sex'

For women, each additional hour of sleep increases the likelihood of sex by 14%. This is according to a new study published in The Journal of Sexual Medicine.

"Sleep disturbance may contribute to sexual complaints and reduced sexual activity," the study concludes.

Although previous studies have looked closely at medical illness, psychological disorders and relationship dissatisfaction as factors that can lead to sex problems for women - such as a lack of sexual fantasies or diminished arousal - sleep problems have been largely overlooked as risk factors for sexual dysfunction.

"As a step toward addressing this gap, we examined the influence of nightly sleep on sexual response and activity in young women," write the authors of the new study.

The researchers say they were interested in exploring the hypothesis that poor sleep duration and quality lead to increased difficulties with sexual function, as no previous studies have explored this. Some studies have found a link between sexual response and untreated sleep-related breathing disorders, but were unable to determine if the poorer sexual response was directly caused by the sleep problems.

For the new study, the researchers recruited 171 healthy women. More than half of the sample reported having at least one sexual partner at the start of the study.

To avoid confounding the results, the study did not include any participants that had recently used antidepressants, which are known to reduce sexual response.

Sleep quality and sexual activity were tracked on daily basis

Every day for 2 weeks, participants were asked questions relating to sexual activity, such as "Did you have sex (oral, anal, hand, vaginal, etc.) with another person within the past 24 hours?" and "Did you masturbate within the past 24 hours?" Regarding sleep quality, they were asked after waking each morning, "How many hours of sleep did you get last night?" and "How long did it take you to fall asleep last night?" and they were also asked to rate their quality of sleep.

The researchers found that each additional hour of sleep increased the likelihood of sex with a partner by 14%, and that vaginal arousal was also improved among women who slept longer on average.

In the conclusion to the study, the authors say their findings prove that good sleep is important for maintaining healthy sexual functioning. Levels of desire, genital response and likelihood of sexual activity are all predicted by both nightly and habitual sleep duration. The researchers explain that these effects were independent of age, sexual distress, daytime fatigue or menstruation.

"These findings suggest that acute sleep disturbance may contribute to sexual complaints and reduced sexual activity," the authors write. They make the following recommendations for clinicians and future researchers:

"Future research may benefit from taking a more comprehensive approach to examining sleep parameters by using both subjective and objective measures. Additionally, the relationship between insomnia and sexual dysfunction may prove to be an overlooked and important area of interest for clinical research. Clinicians may consider assessing patients' sleep habits and insomnia symptoms as potential factors influencing sexual difficulties."

In 2013, the journal Sleep published a study that suggested one night of sleep deprivation causes an increase in men's perceptions of women's sexual interest and their intent to have sex.

The researchers behind the Sleep study found that, when well-rested, both men and women rated the sexual intent of women as being significantly lower than that of men. Following a night of deprived sleep, however, men's rating of women's sexual intent increased to the extent that women were no longer perceived as having lower sexual intent than men.

Sleep deprivation is known to cause frontal lobe impairment, explained the authors, which has a negative effect on "risk-taking sensitivity, moral reasoning and inhibition."