The better your snooze, the hotter your lust life. It's that simple, science shows. It's logical that you're more likely to be in the mood when you're not exhausted and cranky. (Add that to the list of things that could be killing your libido.) But there's solid physiology behind the sleep-sex connection too: Quality rest boosts the action of certain sex hormones, like androgens and estrogen, that lead to arousal. That may help explain why researchers at the University of Michigan Medical School found that getting enough sleep can cause you to crave sex more and may even make it extra-good sex. There's no magic number of hours of rest to aim for, says David Kalmbach, Ph.D., the study's author, but you know you need more if you're feeling groggy on most days. Besides logging enough hours, try these tips for boosting both types of bed action:
# Morning SexLate at night (11 p.m.) is the most common time couples get busy—and it's not ideal. "Your levels of melatonin, a hormone that makes you drowsy, are high then, and your levels of energy-producing hormones like testosterone are low," says Michael Breus, Ph.D., a sleep doctor in Manhattan Beach, California. "That's the exact opposite of what you need for steamy sex." The solution? Have sex first thing, when melatonin is low and testosterone is high—the perfect combo for fireworks.
# Sex After FightAny sort of intimacy, including sex, reduces stress, which means you can sleep easier, report the study's authors. Conflict is especially detrimental to sleep, so if you can, have makeup sex after a fight. Even if it takes a few minutes to cool down first, it's so worth the effort: It can be extra passionate, and you'll wake up feeling more refreshed.