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Why Does Sex Make Men Sleepy?

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Alfred Kinsey, biologist, pioneering sex researcher and founder of the Institute for Sex Research at Indiana University*, once wrote that "a marked quiescence of the total body is the most widely recognized outcome of orgasm," more noticeably among males. Why is that?

Let's get the obvious reasons out of the way first. Sex often, though not always, happens at night in a bed and is physically exhausting. If you're tired to begin with, all that physical exertion only adds to it, and since you're already in bed, it's only natural to be sleepy. Compounding this is the fact that sex dominates your attention when you're having it (and sometimes when you're not), so you don't pay attention to your breathing and wind up breathing shallowly and holding your breath pretty often. These aren't really the sorts of things you want to do during vigorous exercise, as they lead to oxygen deprivation and—all together now—sleepiness.

There's also the biochemistry of the orgasm to consider.

After sex, a man's brain releases a slew of hormones and neurotransmitters. Some of them, like prolactin, oxytocin and vasopressin, have been linked to sleep as well as sex. Prolactin plays a role in sexual satisfaction by counteracting the effects of dopamine** (which is responsible for sexual arousal). It's also been shown that the artificial delaying of an REM sleep period disrupts the rhythm of prolactin release, and that REM sleep is reduced in mice with prolactin deficiencies. Oxytocin and vasopressin have also both been implicated in the body's regulation of sleep cycles. While none of these chemicals are fully understood and their links to sleep aren't concrete, the circumstantial evidence suggests that they may play a part in pulling you off to a post-coital snooze.

What About the Ladies?

The phenomena of men falling asleep soon after sex is a little more well established than women doing the same—at least in that people notice it enough to make jokes about it on sitcoms, and write in to mental_floss asking about it. While I haven't been able to find any science-backed evidence that post-sex sleepiness definitively affects men more than women, there are a few hypotheses floating around as to why it seems that way. In their 2006 book Why Do Men Fall Asleep After Sex?, Mark Leyner and Billy Goldberg, M.D. suggest that exertion during sex depletes the muscles of energy-producing glycogen. Because men usually have more muscle mass, they get more tired. And it's entirely possible that women get just as sleepy, just as fast as men do after orgasm, but women simply have orgasms during sex less often than men do.

*Kinsey left his mark on a different field earlier in his career: entomology. He did his doctoral thesis on gall wasps and researched and published papers about them at the American Museum of Natural History in New York. Of the 18 million+ insects in the museum's collections, about 5 million are gall wasps that Kinsey collected. In return for his collection, Kinsey received $400 and a lifetime membership to the Museum.

**The hormone may also mediate the "sexual refractory period," or the recovery phase after an orgasm during which a man cannot have additional orgasms or achieve an erection.

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science
New Patient Test Could Suggest Whether Therapy or Meds Will Work Better for Anxiety
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Like many psychological disorders, there's no one-size-fits-all treatment for patients with anxiety. Some might benefit from taking antidepressants, which boost mood-affecting brain chemicals called neurotransmitters. Others might respond better to therapy, and particularly a form called cognitive behavioral therapy, or CBT.

Figuring out which form of treatment works best often requires months of trial and error. But experts may have developed a quick clinical test to expedite this process, suggests a new study published in the journal Neuropsychopharmacology.

Researchers at the University of Illinois at Chicago have noted that patients with higher levels of anxiety exhibit more electrical activity in their brains when they make a mistake. They call this phenomenon error-related negativity, or ERN, and measure it using electroencephalography (EEG), a test that records the brain's electric signals.

“People with anxiety disorders tend to show an exaggerated neural response to their own mistakes,” the paper’s lead author, UIC psychiatrist Stephanie Gorka, said in a news release. “This is a biological internal alarm that tells you that you've made a mistake and that you should modify your behavior to prevent making the same mistake again. It is useful in helping people adapt, but for those with anxiety, this alarm is much, much louder.”

Gorka and her colleagues wanted to know whether individual differences in ERN could predict treatment outcomes, so they recruited 60 adult volunteers with various types of anxiety disorders. Also involved was a control group of 26 participants with no history of psychological disorders.

Psychiatrists gauged subjects’ baseline ERN levels by having them wear an EEG cap while performing tricky computer tasks. Ultimately, they all made mistakes thanks to the game's challenging nature. Then, randomized subjects with anxiety disorders were instructed to take an SSRI antidepressant every day for three months, or receive weekly cognitive behavioral therapy for the same duration. (Cognitive behavioral therapy is a type of evidence-based talk therapy that forces patients to challenge maladaptive thoughts and develop coping mechanisms to modify their emotions and behavior.)

After three months, the study's patients took the same computer test while wearing EEG caps. Researchers found that those who'd exhibited higher ERN levels at the study's beginning had reduced anxiety levels if they'd been treated with CBT compared to those treated with medication. This might be because the structured form of therapy is all about changing behavior: Those with enhanced ERN might be more receptive to CBT than other patients, as they're already preoccupied with the way they act.

EEG equipment sounds high-tech, but it's relatively cheap and easy to access. Thanks to its availability, UIC psychiatrists think their anxiety test could easily be used in doctors’ offices to measure ERN before determining a course of treatment.

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Food
A Pitless Avocado Wants to Keep You Safe From the Dreaded 'Avocado Hand'
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The humble avocado is a deceptively dangerous fruit. Some emergency room doctors have recently reported an uptick in a certain kind of injury—“avocado hand,” a knife injury caused by clumsily trying to get the pit out of an avocado with a knife. There are ways to safely pit an avocado (including the ones likely taught in your local knife skills class, or simply using a spoon), but there’s also another option. You could just buy one that doesn’t have a pit at all, as The Telegraph reports.

British retailer Marks & Spencer has started selling cocktail avocados, a skinny, almost zucchini-like type of avocado that doesn’t have a seed inside. Grown in Spain, they’re hard to find in stores (Marks & Spencer seems to be the only place in the UK to have them), and are only available during the month of December.

The avocados aren’t genetically modified, according to The Independent. They grow naturally from an unpollinated avocado blossom, and their growth is stunted by the lack of seed. Though you may not be able to find them in your local grocery, these “avocaditos” can grow wherever regular-sized Fuerte avocados grow, including Mexico and California, and some specialty producers already sell them in the U.S. Despite the elongated shape, they taste pretty much like any other avocado. But you don’t really need a knife to eat them, since the skin is edible, too.

If you insist on taking your life in your hand and pitting your own full-sized avocado, click here to let us guide you through the process. No one wants to go to the ER over a salad topping, no matter how delicious. Safety first!

[h/t The Telegraph]

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