Being tired is the most common reason women give for not having sex with their partner. A survey three years ago showed that it had overtaken headaches as the most popular “excuse”. But an American study last year of more than 1,000 employees from three companies found that 76% of workers felt tired “many days of the week”, so being too tired for sex may well be the truth, rather than a white lie.
We already know that lack of sleep contributes to obesity, heart disease and diabetes as well as reducing life expectancy. So, why wouldn’t it ruin sex, too? There are, however, few studies of the impact of sleep on how women respond to sex.
A pilot study of 171 young women published in this month’s Journal of Sexual Medicine found that sleep affected how much they wanted sex and how easily they became aroused, but that this was unrelated to how tired they actually felt. An extra hour of sleep led to a 14% increase in the odds of sex the next day. More sleep also increased the ease with which women felt “genital arousal”, which was measured on the Female Sexual Function Index’s genital arousal scale. So, will getting more sleep improve your sex life?
The solution
The story of how lack of sleep reduces women’s desire is a complicated one, says the study’s lead author, Dr David Kalmbach from the University of Michigan. In fact, women’s sexual desire itself is complicated. Expert panels say that between 20% and 50% of women have problems with sex – often to do with lack of desire or difficulty in becoming aroused. But how much of this is medical, and how much social and psychological, is highly debatable.
It is estimated that 20% of women have problems with lubrication – which could be due to anything from the menopause to insufficient foreplay. Kalmbach thinks it could also be due to lack of sleep – rapid- eye-movement (REM) sleep in women is associated with increased blood flow to the vagina, while lack of sleep also reduces levels of androgen hormones, which may reduce the desire for sex.
Sex is strangely complicated for such a natural, essential activity. Studies of loss of desire in women often cite psychological factors, such as overfamiliarity with a partner, the institutionalisation of relationships and loss of intimacy. Would sleep help any of these? That said, sleep is at least likely to promote healthy sexual responses through its regulatory actions on hormones, just as it safeguards against medical conditions. The recommended amount for anyone over 18 is between seven and nine hours a night.
