so. When people take testosterone, like anabolic steroids or hormone replacement therapy for

所以。當人們服用睪丸激素，如合成代謝類固醇或激素替代療法為

instance, it has an effect on their muscle mass and strength. But I was curious as to

例如，它對他們的肌肉品質和力量有影響。但我很好奇的是

why this is a thing. How does this hormone influence muscle growth? Well, like with everything

為什麼這是一個東西。這種激素如何影響肌肉生長？好了，就像一切

in the body, the answer is much more complex than a simple cause and effect. In today's

體中，答案要比簡單的因果關係複雜得多。在今天的

video, we'll look at the interaction between hormones and hypertrophy.

視頻，我們來看看激素和肥大之間的相互作用。

The big, bulky skeletal muscles that we see with the naked eye are made of bundles of muscle fibers. These things

我們肉眼所見的碩大的骨骼肌是由肌纖維束組成的。這些東西

are living cells with nuclei, mitochondria, and active metabolisms. Because of that, they're

是具有細胞核、線粒體和活躍的新陳代謝的活細胞。正因為如此，它們是

dynamic structures — they can respond to stresses placed on them. That might mean growing

動態結構--它們可以對施加在它們身上的壓力做出反應。這可能意味著增長

in size, or undergoing hypertrophy to meet the demands of weight lifting or your favorite

肥大，或為了滿足舉重或你最喜歡的運動的要求而進行肥大。

exercise. That might also mean shrinking, or undergoing atrophy, if the muscle isn't

鍛鍊。這也可能意味著萎縮，或進行萎縮，如果肌肉不。

being used heavily.  Now, to understand how a muscle grows, we need some basic skeletal

被大量使用。 現在，要了解肌肉是如何生長的，我們需要一些基本的骨架。

muscle anatomy. Within each muscle cell are strands of stiff proteins called myofibrils,

肌肉解剖學。在每個肌肉細胞內，都有一串稱為肌纖維的硬蛋白。

which contain long proteins called filaments arranged into a parallel pattern that lets

含有長長的蛋白質，被稱為絲狀物，排列成平行的模式，可以讓你的生活更美好。

them slide back and forth past each other. This sliding mechanism is ultimately what allows

彼此之間來回滑動。這種滑動機制最終使得

our muscles to produce tension. And if we zoom out to the muscle fiber's surface,

我們的肌肉產生張力。而如果我們放大到肌肉纖維的表面。

we see tiny cells called satellite cells that hang out on the edge of muscle fibers underneath

我們會看到一些微小的細胞，叫做衛星細胞，它們掛在肌肉纖維的邊緣，在肌肉纖維的下面

the connective tissue. These things are essentially dormant muscle cells, kind of like muscle

的結締組織。這些東西本質上是休眠的肌肉細胞，有點像肌肉一樣。

stem cells. When our muscles produce a high amount of tension like during resistance exercise,

幹細胞。當我們的肌肉產生大量的張力，比如在抗阻運動中。

those myofibrils incur a little bit of damage. This produces an inflammatory response at

這些肌纖維會受到一點損傷。這產生的發炎反應在

the muscle which then promotes healing. That inflammation also wakes up the satellite cells

肌肉，然後促進癒合。發炎也喚醒了衛星細胞。

which prompts them to fuse into the muscle fiber they're attached to. And each satellite

促使它們融合到它們所附著的肌肉纖維上。而每顆衛星

cell has a nucleus with the instructions for making more of those contractile proteins.

細胞有一個細胞核，裡面有製造更多收縮蛋白的指令。

And increases in muscle size mostly comes from adding those proteins to muscle. I say

而肌肉體積的增加，大多來自於將這些蛋白質添加到肌肉中。我說

that hypertrophy comes mostly from more myofibrils because we can also grow the connective tissue

肥大主要來自於更多的肌纖維，因為我們也可以生長結締組織。

within muscles, or increase the volume of water in the muscles, and a few other things. So

肌肉內，或增加肌肉中的水容量，以及其他一些東西。所以

then where does testosterone come in? Well, each muscle cell has receptors for androgen

那麼，睪丸激素在哪裡來？每個肌肉細胞都有雄性激素的受體。

hormones which lets them receive messages from hormones like testosterone. Once testosterone

激素，讓它們接收來自睪丸激素等激素的資訊。一旦睪丸酮

is in the cell and binds to the receptor, it moves over to the nucleus where we keep

是在細胞中，並結合到受體，它移動到核，在那裡我們保持。

our DNA, then it encourages transcription of certain genes that make more proteins.

我們的DNA，那麼它鼓勵某些基因的轉錄，製造更多的蛋白質。

If the DNA is a recipe for protein, then testosterone gets the cell to read the recipe and make

如果DNA是蛋白質的配方，那麼睪丸激素就會讓細胞讀懂配方，並製造出

more of that protein. Testosterone can also stimulate the release of other growth factors,

更多的這種蛋白質。睪酮還可以刺激其他生長因子的釋放。

and promote the replication and activation of those important satellite cells. So all

並促進這些重要衛星細胞的複製和活化。所以，所有

in all, testosterone promotes muscle hypertrophy by stimulating the creation of proteins, or

總的來說，睪酮通過刺激蛋白質的產生，或促進肌肉肥大。

anabolic processes. But it doesn't just build up proteins, it also inhibits protein

合成代謝過程。但它不只是建立蛋白質，它還能抑制蛋白質。

breakdown, or catabolic processes. Now, that answered my question from the top of the episode,

分解，或分解過程。現在，這回答了我從頭到尾的問題。

but as always, learning one thing prompts ten more questions. Like, if testosterone

但和往常一樣，學會了一件事，就會產生十個更多的問題。比如，如果睪丸激素

helps my muscles grow after training, how can I make testosterone more available for

訓練後有助於我的肌肉生長，如何才能讓睪丸激素更多的為我所用呢？

my muscles? The first thing you can do is have testes. For those wondering, yes, the

我的肌肉？首先你可以有睪丸。對於那些想知道的人來說，是的。

name for the hormone comes from testes plus stero - since it's a steroid hormone. If

激素的名稱來自睪丸加固醇-因為它是一種類固醇激素。如果

you do, the vast majority of your testosterone comes from the Leydig Cells in the testes.

你做，你的睪丸激素的絕大多數來自於睪丸中的萊迪格細胞。

If you don't, you still make testosterone in the ovaries and adrenal cortices, albeit,

如果你不這樣做，你仍然會在卵巢和腎上腺皮質中製造睪酮，儘管。

much less. It doesn't matter what kind of hardware you have. You have a way to make

少得多。不管你有什麼樣的硬件。你有辦法讓

testosterone. It's hard to say exactly how much less, though. In my research, I saw figures anywhere

睪酮。很難說到底有多少少，雖然。在我的研究中，我看到的數字在任何地方

from one fifth to one fortieth. So take some of those normative values with a grain of

從五分之一到四十分之一。所以，對這些規範性的價值，我們要帶著一些

salt. The second thing you can do is be a young adult. The testes make much more testosterone

鹽。第二，你可以做一個年輕的成年人。睪丸分泌的睪丸素要多得多。

after puberty than before but around ages 35 to 40 years old, they start to create 1

青春期後比青春期前，但在35歲至40歲左右，他們開始產生1。

to 3 percent less testosterone every year. If your primary way of making testosterone

每年少3%的睪酮。如果您的主要方式使睪丸激素

is through the ovaries and adrenals, the same rules apply. You make more after puberty and

是通過卵巢和腎上腺，同樣的規則適用。你使更多的青春期後和

make less in your late twenties, early thirties. What about a weight lifting routine though?

二十多歲，三十出頭的時候賺的少。不過日常舉重呢？

Right after resistance training, the testes do secrete more testosterone, but only for

就在抗阻訓練後，睪丸確實會分泌更多的睪丸素，但只是針對於

about 30 minutes. The exercise you do might influence that. According to a review from

大約30分鐘。你做的運動可能會影響到這一點。根據一篇來自

2010 and another from 2017, high volume and short rest periods usually induced the largest

2010年和2017年的另一個，高容量和短暫的休息期通常會引起最大的

acute testosterone release. But we really don't know if a long term weight lifting

急性睪丸酮的釋放。但我們真的不知道，如果長期舉重，

regimen will cause your body to produce more testosterone all the time. Different studies

療程會導致你的身體產生更多的睪丸激素所有的時間。不同的研究

have come up with different results, with some concluding that long term weightlifting

得出了不同的結果，有人得出結論，長期舉重的

does increase a person's base level of testosterone while some research didn't

並增加一個人的基礎水準的睪丸激素，而一些研究沒有

see any differences. Many of the participants in the trials still get stronger and bigger

看到任何差異。許多參加試驗的人仍然會變得更強壯和更大。

muscles, they just didn't increase base level testosterone. In reality, our hormones

肌肉，他們只是沒有增加基礎水準睪丸激素。在現實中，我們的荷爾蒙

interact with multiple feedback loops from other hormones after exercise. Reviews of

與運動後其他激素的多個反饋環路相互作用。評論

resistance exercise and hormones usually touch on growth hormone and insulin-like growth

抗性運動和激素通常觸及生長激素和胰島素樣生長。

factor in addition to testosterone. So while this one hormone gets a lot of attention,

因素之外，還有睪丸酮。所以，雖然這一種激素備受關注。

we need to remember that it's just one piece of a much larger system. Thanks for watching

我們要記住，這只是一個更大的系統中的一部分。謝謝你的觀看

this episode of Seeker Human. If you want to learn more about hormones, we did an explainer

這一集的探索者人類。如果你想了解更多關於荷爾蒙的資訊，我們做了一個解釋。

video in the last season of Human that you can find here. Otherwise, make sure you're

視頻在人類的最後一季，你可以在這裡找到。否則，請確保你是

subscribed to us on Youtube so you know when we drop new episodes. Thanks for watching.

訂閱我們在Youtube上，所以你知道當我們放棄新的情節。謝謝你的觀看。