Some of us have been asking why guys get sleepy after sex. Many men barely leave time for the bed sheets to settle before they make a beeline for the land of nod, but is there any scientific reason why one gender might be more prone to a post sex snooze?

As it occurs, there is. The author of Scienceline, a project of New York University's Science, Health and Environmental Reporting Program, takes a look at the possible factors that could be involved in this phenomenon.

This answer is provided by

Melinda Wenner Moyer

Science journalist and author

The correlation between sex and snoring is an annoying fact of life for many women. Dave Zinczenko, the author of "Men, Love and Sex: The Complete User Guide For Women," told Huffington Post writer Arianna Huffington that men go to sleep because women don't turn into pizzas.

I don't think I'll ever become a pizza, and I won't have the foresight to order one before. A better explanation will have to be done. The phenomenon of sleeping after sex seems to be more pronounced in men. That leads them into the land of nod.

Sex frequently takes place at night, in a bed, and is physically exhausting for both the man and the woman. It is normal for a man to feel sleepy after sex.

In order for a person to reach orgasm, they need to let go of fear and anxiety. It's possible that doing so causes the tendency to snooze.

The orgasm is made up of many different substances. A cocktail of brain chemicals is released during ejaculation. The release of prolactin leads to the feeling of sexual satisfaction, and it also leads to the time a man must wait before giving it another try. Men who are deficient in prolactin have a quicker recovery time.

Animals that are injected with prolactin become tired immediately. It is thought that the release of prolactin during orgasm may cause men to feel sleepy.

Prolactin explains why men are sleepier after sex. Intercourse orgasms release four times more prolactin than masturbatory orgasms.

Two chemicals released during orgasm are linked to sleep. melatonin is the main hormone that regulates our body clock. Reducing stress is thought to lead to relaxation and sleep deprivation.

There are evolutionary reasons for post-sex sleepyness. It's difficult to explain. A man's primary goal is to produce as many children as possible, and sleeping doesn't help in that regard. Re-energizing himself through sleep may be the best use of his time.

Although there is conflicting information as to whether women feel sleepy after sex, a woman often falls asleep with the man anyways, which is good news for him. The man may be ready to go again when he wakes up.

It is possible that the side effect of sleepyness is related to a more important reason for the release of oxytocin and vasopressin. Pair bonding, a social attachment human mates commonly share, is also associated with both chemicals. Sex and emotional attachment may be partially explained by the release of brain chemicals during orgasm. Cooperative child rearing maximizes the young one's chances for survival if the couple have a baby.

There are many potential biochemical and evolutionary reasons for post-sex sleepy, but no one has yet pinpointed the exact causes. We females need to get used to it because it doesn't look like it will change soon.

If you are upset with the ubiquity of post-sex snoring, remember that things could be worse. Almost half of English men fall asleep during sex.

Coitus interruptus is a topic that should be discussed.

The answer is provided by Scienceline, a project of New York University.

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