You might find it superfluous or tiresome when friends share their times for their latest mile run on social media.
朋友们在社交网络上分享自己最近一次长跑的里程数，你可能觉得这种行为既肤浅又磨人。

But a new study finds that it will actually motivate you: Exercise, it turns out, can be contagious.
不过，新研究证实，他们的行为其实对你有激励作用哦：事实证明，运动是会传染的！

The study examined exercise habits of more than one million runners across a five-year period.
这项研究历时五年，对超过一百万名长跑者的锻炼习惯进行了调查。

"Knowing the running behaviors of your friends as shared on social networks can cause you to run farther, faster, and longer," study author and Massachusetts Institute of Technology professor Sinan Aral said.
“通过社交网络了解到朋友在进行体育锻炼，这能激励你锻炼时跑得更远、更快、时间更长。”该研究项目的研究作者，麻省理工学院Sinan Aral教授说。

Previous studies on health and lifestyle have found similar contagions for phenomena like obesity, anxiety and weight loss.
在有关健康与生活方式的前期研究中，人们已经发现在肥胖、焦虑和减肥等事情上也有类似的传染现象。

Pinning down this effect has limitations, though, like people's propensity for following others like them.
不过必须一提的是，这种传染现象也有局限性，比如人们是否倾向于受同类人的影响。

Plus, they included self-reported estimates from the people themselves on their eating or exercise habits.
同时，人们对自己的饮食习惯、锻炼习惯的自我评估也要考虑在内。

The running was more contagious for men than for women, in that they ran longer distances or at a speedier pace if their male friends shared what they did.
男性比女性更容易在锻炼上受他人影响，当他们的男性朋友晒出自己的运动成就时，他们锻炼时跑出的路程更远，速度也更快。

The same goes for their female friends but it wasn't as significant.
这种现象在女性身上同样存在，但并没有男性那么显著。

On the other hand, women apparently didn't pay much mind to their male friends and nearly exclusively changed up their patterns only based on other women.
不仅如此，女性对自己的异性朋友显然不太关注，她们改变自己的锻炼模式几乎完全是受其他女性的影响。