Men fall asleep after sex because they’re tired. If they’ve managed to achieve orgasm, then their bodies have been put into a state of bliss and relaxation. It only follows that if a body is relaxed enough, it will fall asleep. This is even a problem with people trying to learn meditation, as they may become so relaxed that they fall asleep.
According to Dr. Billy Goldberg and Mark Leyner, authors of a book entitled Why Do Men Fall Asleep After Sex: More Questions You’d Only Ask a Doctor Only After Your Third Whiskey Sour (Three Rivers Press; 2006), the male brain releases the hormones oxytocin and prolactin, which not only relax the muscles but can make a man very drowsy.
In a survey done by University of Surrey, 48% of 10,000 sexually active men in the UK not only fall asleep after sex, but during sex. Although this is not the most seductive thing an English man could admit to, it may show that English men are honest when it comes to answering surveys.
No matter how often one reads about hormones, it can be a little disturbing to have your sexual partner sawing wood while you’re still raring to go. An active mind may read all kinds of things into the man’s post-orgasmic slumber. The biggest fear is that the man is bored with his partner and that’s the real reason why he falls asleep.
Falling asleep next to someone can be seen as a sign of trust. Our ancestors probably found strength in numbers so that someone was always awake and on guard in order to prevent the tribe from being wiped out by sabre-toothed tigers or a rival tribe. This may also explain why many women are wide awake after sex. Their genes have programmed them to be on the lookout for predators while everyone else is asleep.
Timing Is Everything
Keep in mind that, despite the stereotype, not all men will fall asleep right after sex. Some will become energized and ask their partners if they wish to have sex again. Some will become very hungry and some will want to engage in relaxing and pleasurable activities like smoking, eating a pizza, watching television or soaking in a hot bath.
But the stereotype that men usually fall asleep after sex is persistent and must be for good reason. The reason most likely is that sex is usually relegated to the activity that takes place right before going to sleep. Throughout history, men have had a long day tilling the fields, slaughtering the heathen or running the rat race. Before sex is even initiated, the man is already tired.
In order to try and keep the man awake, sex should take place at some other time than when he usually falls asleep. But it is not guaranteed to work. The partner of such a man should not be upset if the man falls asleep after sex. However, he or she should be upset if the man falls asleep during sex.
Daily Mail Online. “Why men fall asleep after sex.” David Wilkes. 3 May 2005. http://www.dailymail.co.uk/health/article-338126/Why-men-fall-asleep-sex.html
“Why Do Men Fall Asleep After Sex: More Questions You’d Only Ask a Doctor Only After Your Third Whiskey Sour.” Dr. Billy Goldberg and Mark Leyner. Three Rivers Press; 2006.
Life’s Little Mysteries. “Why Do Guys Get Sleepy After Sex?” http://www.livescience.com/mysteries/070315_sex_sleep.html