Do you and your partner both manage to stay awake after sex, basking in the joy of that blissful moment together?
Or does one of you uncontrollably drift off to sleep, leaving the other to enjoy the period of bliss on their own?
If the second sounds more like you or your partner, then you’re definitely not alone.
But is it just men that tend to pass out after sex, or do women too? And is it selfish behavior or are men at the mercy of their biological design?
Research explains why men fall asleep
In 2012, the French neuroscientist Serge Stoleru published research into the reason for men’s post-sex slumber which made headlines around the world.
He found that there are biological processes at work which lead to men feeling sleepy after climax. Neuroimaging scans show that the prefrontal cortex area of the brain reduces in activity after climax.
Being the area of the brain associated with consciousness, information processing and mental activity, this helps explain why men feel sleepy.
Following that, two more areas of the brain (the cingulate cortex and amygdala) then stop the man from having sexual thoughts. This leads to the refractory period during which the man rests and recovers.
To switch off this sexual thinking, the body releases hormones such as oxytocin and serotonin. These hormones are further associated with sleep and relaxation. Serotonin is a precursor to melatonin, which is the hormone that regulates your internal body clock.
In addition, prolactin is released after orgasm, which is another hormone associated with relaxation, satiation and sleep.
Prolactin also mediates the recovery time, as shown by the fact that men with lower levels of prolactin tend to recover faster. And studies have shown that animals injected with prolactin become tired immediately.
So it would appear that men aren’t in fact avoiding cuddles or being selfish. They simply don’t have control, with their body just shutting down temporarily.
There are several other ideas about why men fall asleep after sex, ranging from common sense possibilities to evolutionary theories.
For example, it could simply be that sex is often quite tiring. Sometimes men do engage in prolonged and physically exerting behavior.
The muscles may become depleted of glycogen, the intense breathing might tire them out, and the drop in blood pressure and heart rate might all contribute in some way.
One possible evolutionary theory is that men may need to rest so they can continue with their drive to produce offspring.
Women, however, may be more likely to want to engage in couple-bonding activities like talking and cuddling to foster long-term commitment.
And yet another evolutionary theory suggests that men shut down after sex to prevent them from moving on to the next partner. This helps keep them in check and to stick with one partner to eventually help with raising a family.
Why don’t women fall asleep after sex?
Anecdotally, it seems that men are the ones in the dog house when it comes to their post-sex behavior. But in fact, the evidence is actually conflicting as to whether women do or don’t feel sleepy after sex too. If they don’t fall asleep so easily though, why might this be?
Whilst some women naturally fall asleep with their partner, there could be a number of possible biological explanations for those that don’t:
1. Women don’t experience the exact same release of the potent cocktail of hormones which are associated with relaxation and sleep.
2. Women don’t have the same refractory period as men – in fact women tend to stay aroused much longer once they’ve experienced the high level of arousal associated with climax.
3. Women don’t always climax as easily as men do, and therefore the release of the hormones associated with relaxation and sleepiness is less likely to happen.
No difference in how long it takes men and women to fall asleep
Kruger and Hughes published a study in in 2011 which suggests that there’s no significant difference between the time it takes men or women to fall asleep after sex. Their online survey of 456 people therefore contradicts conventional wisdom entirely.
They do suggest that observational studies would be better than an online survey to measure this phenomenon more accurately. However, the results show that men and women believe they fall asleep in roughly the same time period after having sex.
Also interesting is that the study found that when partners don’t have sex, women tend to fall asleep quicker than men.
Could sex be a natural insomnia cure?
To answer this question, we also need to consider how sex impacts on other factors that are important in sleeping well.
1. Research has in fact shown that contrary to historical belief, exercise at any time in the day could help you sleep better. If the sex is vigorous enough, perhaps it will wear you out.
2. A raised bedroom and body temperature isn’t ideal for falling asleep. In fact, a falling body temperature is preferable. Perhaps then if you do have sex at night, it might be best to try to keep the room cool. Or even have a cool shower after sex before drifting off.
3. If you don’t experience a climax and therefore the relaxing hormones, could the increased adrenaline then become an issue for insomniacs? All the more reason to try and ensure both partners reach climax!
4. Contrary to the above point though, we also know that relaxation of the mind is very important in falling asleep. If sex with or without a climax can help reduce all the busy thoughts that can keep you awake, then that can only be a good thing.
5. A key point in managing insomnia is to maintain a regular sleep schedule. And the unpredictability of the timings of sexual desires and activity has the potential to seriously disrupt this. But to suggest a curfew for sexual activity could be going a step too far…
It does seem then that there’s strong evidence for men’s innocence when it comes to falling asleep after sex. They just can’t fight all the effects of the powerful hormones flooding their body.
It’s probably best to draw your own conclusions about whether sex is a viable insomnia cure or not though.
As an insomniac you should probably be grateful if it brings you the occasional release from the suffering of sleeplessness.
If your partner is the one who falls asleep straight away after sex though, leaving you once again to deal with your insomnia, then perhaps go easy on them and remember that they aren’t being selfish (hopefully).
If you feel strongly about it, then you could perhaps talk to them about it and encourage them to resist the pull of their biological mechanisms. Ask them to spend some time with you in what can be one of the most beautifully intimate moments between a couple.
If you’re a man, do you find that you naturally fall asleep after sex or not? If you’re a woman, do you find your partner often falls asleep when you wish he’d stay awake and cuddle for a while? How does it make you feel?
Do you think it’s possible to fight the biological processes at work? Do you think people should try and resist them to spend quality time together? Feel free to share you views and thoughts in the comments below.