Once it's generated, irisin improves bone density and strength.

一旦产生，鸢尾素就能提高骨骼密度和强度。

But, since they've only just figured out that irisin in humans exists, that's a long way off.

但由于他们只得出鸢尾素存在于人体中，还有很长的路要走。

That irisin, which builds bone, would promote the production of sclerostin, which destroys it, may seem counterintuitive.

而能生成骨骼的鸢尾素，竟然会促进会破坏骨骼的骨硬化蛋白的产生，这似乎违反常理。

Boning up on the actions of irisin could help us work out how we can derive the most from our workouts.

专注研究鸢尾素的行为能帮助我们找到从锻炼中获得最大益处的方法。

Maybe! The key is a hormone whose existence in the human body was only confirmed early in 2015: It's called irisin.

或许吧！答案就是一种2015年年初才被确认存在于人体的荷尔蒙：鸢尾素。

But, since they’ve only just figured out that irisin in humans exists, that’s a long way off.

但是，由于他们只是刚刚发现人体中存在鸢尾素，因此还有很长的路要走。

Irisin turns out to be one of the many hormones released by your body when you exercise, along with more well-known ones like testosterone and adrenaline.

鸢尾素是多种荷尔蒙中一种在运动时产生人体所释放的荷尔蒙，会与更为熟知的睾酮荷肾上腺激素等一起产生。

To find out how, Bruce Spiegelman and his colleagues at the Dana Farber Cancer Institute and Harvard Medical School took cultured bone cells and located the receptor to which irisin binds.

为了弄清改善方式，布鲁斯·斯皮格尔曼和他在达纳法伯癌症研究所以及哈佛医学院的同事提取了培养骨细胞，并定位了鸢尾素结合的受体。

Dr. Celi worked with researchers at the US National Institutes of Health, in Bethesda, Maryland. They already knew the body produces irisin when we do physical exercise.

Celi 博士与位于马里兰州贝塞斯达的美国国立卫生研究院的研究人员一起工作。他们已经知道当我们进行体育锻炼时，身体会产生鸢尾素。

But while testosterone stimulates muscle growth and repair, and adrenaline stimulates the breakdown of fat and sugar in your bloodstream for energy, irisin stimulates the production of mitochondria and UCP1 in your white fat cells.

但是，虽然睾丸激素会刺激肌肉生长和修复，肾上腺素会刺激血液中脂肪和糖的分解以获取能量， 但鸢尾素会刺激白色脂肪细胞中线粒体和 UCP1 的产生。