Key to a good sex life? More sleep

Women looking to jump-start their sex life may want to spend more time in bed.

Sleeping.

That's the conclusion of a new study that suggests that each additional hour of sleep increased by 14 percent the likelihood a woman would engage in sexual activity with a partner the next day.

"Our study showed that good sleep is important for healthy sexual desire and arousal in women, even when women are psychiatrically and medically healthy," said study author David Kalmbach, a researcher at the University of Michigan Sleep and Circadian Research Laboratory.

Kalmbach and several colleagues evaluated 171 women, all college-age, who kept diaries of their sleep for 14 consecutive days and reported whether they engaged in sexual activity the next day. Longer sleep time was linked with greater sexual desire the next day. Women with longer average sleep duration said they had better genital arousal than women with shorter sleep time. On average, the women reported sleeping 7 hours, 22 minutes.

Other studies have suggested that short sleep time and poor sleep quality lead to poor female sexual response, Kalmbach said. But most studies have been a ''snapshot in time," looking at just one time point.

"I think these findings suggest that taking a closer look at sleep health in women with sexual complaints is a worthwhile endeavor," Kalmbach said, "as poor sleep may lead to sexual problems."

Kalmbach said it's not known how lack of sleep might affect sexual desire. But he said it's not simply due to changes in mood, for instance, as the study assessed the women's levels of depression and anxiety.

"Some previous studies have hypothesized that sleep can affect hormone levels, which may cause changes in desire and arousal," he said. "But I think overall, more research is needed in this area to identify the underlying mechanisms more confidently."

"The message," Kalmbach added, "is that sleep health is important for many areas of our daily living. Good sleep has been shown to improve mood, energy, concentration, overall health, and, now, sexual desire and arousal."

The study findings were published online March 16 in the Journal of Sexual Medicine.

Dr. Nathaniel F. Watson is president-elect of the American Academy of Sleep Medicine and professor of neurology at the University of Washington, in Seattle.

He called the new research "one of the few studies to assess the relationship between sleep duration and sexual health." But, he added, "you have to be a little bit cautious about drawing any conclusions from this because it is just an association study," and doesn't prove cause-and-effect.

Even so, Watson added, "I still think the findings are compelling and certainly warrant follow-up with interventional studies."

For now, Watson said the take-home message is this: "You could add it to a long list of reasons why getting a proper amount of sleep is good for your health."

Kalmbach had this advice: "It there's anything women or their partners can do to help promote good sleep for one another, whether it's helping out around the house to reduce workload, planning romantic getaways, or just practicing good sleep hygiene, it could help protect against having problems in the bedroom."