If you’re someone who enjoys distance running, you might’ve felt a sensation of happiness,
跑步者的愉悦(runner’s high) 一般来讲是指运动带给人们的平静或轻微不适
calm, or reduced pain that sets in after a workout—commonly known as runner’s high.
Since the 1980s, runner’s high was thought to be caused by chemicals called endorphins.
Remember the line from Legally Blonde?
“Exercise gives you endorphins, and endorphins make you happy!”
但是 如今科学家们也不能确信这所有的一切(runner’s high)都是脑内啡导致的
But now, scientists aren’t convinced that endorphins should get all the credit.
The real culprit might be endocannabinoids, a group of chemicals in your body that act
like the compounds in marijuana that cause a high.
Endorphins bind to what are known as opioid receptors on neurons all over your body, affecting
other chemical signaling that your brain interprets as pain.
在过去 人们认为是脑内啡导致了这一切 因为它可以缓解肌肉疼痛
Because endorphins can cause pain relief in your muscles, they were thought to cause all the feel-good parts of runner’s high.
但是 结果发现脑内啡分子结构过大 无法通过血脑屏障
But endorphins, it turns out, are too big to pass through the blood-brain barrier, a
highly selective membrane that protects the brain from potentially harmful stuff in the bloodstream.
So they probably don’t cause the general feelings of happiness that come with runner’s
high, because they’re not interacting with brain cells.
Instead, scientists think it might be the endocannabinoids.
Endocannabinoids interact with the same systems in your brain as THC in marijuana does, but
your body naturally makes them.
They’re involved in things like soothing anxiety and reducing pain sensitivity.
In 2015, a group of researchers showed that mice produced more of an endocannabinoid called anandamide after running on a wheel for around
为了测试伴随着跑步者愉悦的疼痛缓解 将奔跑的老鼠和没有奔跑的老鼠放在热盘上 使其产生疼痛感
To test for the pain-relief that comes with runner’s high, mice who ran and mice who didn’t were placed on a hot plate to cause pain.
而在热盘上跑步的老鼠 其血液中有更多的大麻素 并且有长时间明显的激动
And the mice who ran had more anandamide in their blood and took longer to get noticeably agitated on the hot plate.
Then, the researchers ran the experiment again.
这次 他们给了一些跑步老鼠一种药物 它们可以阻止内啡肽产生任何影响 但是当老鼠被放在一个热盘上 它们在这方面表现得更平静
This time, they gave some of the running mice a drug to block endorphins from having any effect, but the mice still acted calmer when
they were plopped on a hot plate.
The researchers gave other running mice a drug that blocks anandamide from binding to receptors.
These mice were more anxious and sensitive to the hot plate—just like the non-runners.
所以 根据这项研究 似乎是大麻素有助于缓解跑步者的疼痛和焦虑 但是内啡肽并没有太大作用
So, according to this study, it seems like anandamide contributes to the pain and anxiety relief of runner’s high, but endorphins
not so much.
At least in mice.
But what about humans?
2012年 一项研究有一些人类 狗和雪貂在跑步机上跑了半个小时
In 2012, a study had a few humans, dogs, and ferrets run on treadmills for half an hour,
and found that endocannabinoid levels in blood went up in humans and dogs—which are both better adapted to running.
And a 2011 study involving 11 healthy male cyclists suggested that anandamide production from exercise might increase neurotrophin levels,
a kind of protein that can adjust connections between neurons, and have some antidepressant effects.
Because of small sample sizes, though, it’s hard to say if these studies mean something for all of us.
So there’s a good chance that endocannabinoids could be involved in runner’s high, but there’s a lot we still don’t understand
about our bodies!
Thanks for asking, and thanks especially to all of our patrons on Patreon who keep these answers coming.
If you’d like to submit questions to be answered, or get some videos a few days early,
go to patreon.com/scishow.
And don’t forget to go to youtube.com/scishow and subscribe!