Some
 people have described sex as one of the sweetest things on earth, and 
even if it is stressful and requires a lot of strength to do, especially
 for men, it is a rigorous exercise many people would gladly undertake 
over and over again.
Though, it is no secret that many men 
nod off straight after sex, some women also sometimes feel sleepy after 
sex but the phenomenon seems more pronounced in men. To women, the 
obvious sign of complete ‘shutdown’ by men moments after a passionate 
encounter is practically frustrating, and could be accompanied with a 
loud buzz of snoring.
Scientists have given men the perfect 
excuse for feeling sleepy after sex: ‘they just cannot help themselves, 
and not that they are just selfish.’
It is easy to think that men sleep off 
after sex because they are tired, but findings have shown that it goes 
beyond that. Scientists have said that men really do need to sleep after
 sex when they climax because their brains become flooded with 
sleep-inducing chemicals such as oxytocin, serotonin and prolactin.
Also, the blood rush after the climax 
depletes the muscles of energy-producing glycogen and because men 
typically have higher muscle density than women, they become more tired 
after sex.
In other words, the answer to the 
question, ‘why do men fall asleep after sex’ may be as simple as saying 
that they have very little control over their bodies at that point; 
hence, it literally shuts down.
When a group of scientists led by a 
French Neuroscientist, Serge Stoleru, in a study scanned some men’s 
brains before and during orgasm, they found that the cerebral cortex, 
which is the ‘thinking’ area, shuts down almost immediately after 
orgasm. After this, two other areas, the cingulate cortex and amygdale 
direct the rest of the brain to deactivate from sexual desire.
Stoleru, whose research was published in
 the Journal Neuroscience and Biobehavioural Reviews, said the human 
brain is involved in all the successive steps of sexual behaviour.
Also, neuroimaging scans show that, 
after orgasm, men tend to experience decreased activity in the 
prefrontal cortex, the area of the brain associated with consciousness, 
information processing, mental activity and responding appropriately. 
This, according to scientists, helps to explain why men feel sleepy 
after sex.
As this happens, a surge of chemicals 
such as oxytocin and serotonin flood the brain creating a powerful 
sleep-inducing effect while reducing stress levels, boosting relaxation 
and sleepiness.
To take it further, when prolactin 
chemical associated with feeling satisfied is released into a man’s 
system during orgasm; it is likely that it causes the man to feel 
sleepy, which further explains why men feel sleepier after intercourse 
than after masturbation. However, previous research showed that men who 
have lower prolactin are less tired and tend to feel less sleepy after 
sex.
Stoleru added, “After men have an orgasm
 they usually experience a refractory period when they cannot be 
aroused, while women don’t seem to have such a strong refractory period 
and may be asking for more or some intimate attention when their 
partners just want a rest.
A businesswoman, Mrs. Oni Juliet, said 
she had been wondering why her husband slept after sex adding that she 
expected more from him, being a young man.
She said, “Most of the time, he sleeps 
off shortly, or even almost immediately after he reaches orgasm, while I
 would be left hanging, longing for him to hold or kiss me. But he would
 just be beside me, like someone who has shut down completely. It could 
be frustrating, you know.
“Really, I expect more from him because 
we are still both very young. He deflowered me on our wedding night, I 
have not had any experience before now, but I find it very disturbing. 
Once he goes for first round, he knocks out, and the next thing is to 
start snoring.”
A Director of Sleep at the University of
 Surrey, United Kingdom, Dr Neil Stanley, said as frustrating as it is 
for most women that their male partners just roll over and fall asleep 
after sex, men are not completely at fault and are not entirely to 
blame. “Humans are the only animals in which sleep and sex are linked 
and while often seen as just a poor excuse, there are scientific reasons
 why men feel tired after sex,” she said.
More reasons it could be wrong timing to
 hope to have a conversation with your man after sex, because you may as
 well be talking to yourself.
Some reviewers of the study said a 
constructive way to tackle the problem could be for wives to express 
their distress to their husbands and ask if they could try to dedicate 
few minutes after making love to them. Another could be to have sex 
outside the bedroom, possibly earlier in the day, maybe in the bathroom,
 having glasses of their favourite drink by the tub to make the 
experience more sensual.
However, one thing is for females to get
 used to it, because it is not likely to change anytime soon. In fact, 
it could be worse in some cases because a recent survey of 10,000 
English men revealed that 48 per cent actually fall asleep during sex, 
so, be grateful if he falls asleep after, and not during sex.
A Consultant Psychologist, Prof. Toba 
Elegbeleye, said sex takes a lot of energy to complete and that there is
 tendency for the brain and the entire system to want to rest when such 
intense energy is exhibited. He cautioned that where the sexual activity
 took place also determined if the sleep would be possible or not.
He said, “When you indulge in sex, which
 usually takes place at night when people sleep naturally, it comes with
 a level of intensity that involves all your energy and whatever you can
 muster to make it have a shaking effect, after which the multi-nerve 
ends are relaxed. This makes people sleep easily.
“It also depends on where you do it. 
Usually, if it is a legal encounter, which takes place in your own 
bedroom where you are comfortable, you might sleep, which is different 
from when you do it in your car or somewhere else under duress, that is 
not so comfortable.
“Another factor that could aid sleeping 
well after sex is eating good food prior to the act because you may not 
be able to do it well if you are hungry and the body entertains only one
 urge at a time and hunger is as strong an urge and a drive as sex is. 
Other factors could be to have a pleasant room atmosphere with a good 
bed and if there is no thought of threatening financial burden or 
security issues in mind.”
A Clinical Psychologist, Mr. Femi 
Agberotimi, said there are certain physiological reactions during and 
after sex that occur in both genders that have been identified to 
induce/enhance sleep.
“The neurotransmitter dopamine, released
 during orgasm triggers a stress-reducing, sleep-inducing response that 
may last up to two hours. Hormones such as Oxytocin and Prolactin which 
are released in a much quantity during sex than in the usual state have 
also been identified to enhance sleep because of the good feelings they 
produce.
“Other physiological changes that occur 
during sex which could translate to getting tired and falling into sleep
 include the increase in heart rate, respiration and blood pressure as 
well as changes in the muscle tone which could put the body in the same 
state with someone who ran 100meter race,” he added.
Source: The Punch 
