朗读者：Hurdy

朗读文本：

If your friends are happy, it turns out you’re more likely to be happy too. If your friends are overweight, you are likely to put on weight. These “friend effects”, the mutual effects among friends, have been shown in studies. And now researchers have found that you may also be influenced by your friends who do exercise often.

The research shows that women tended to be influenced by the female runners in their networks. And less active runners tended to influence more active runners to run more. Even the behavior of one city’s runners could affect the behavior of runners in another city. If someone is influenced by and influences his social network in a strong way, he must take his social network into consideration when he changes his life style. In other words, if you want to insist on doing exercises, appeal to your friends and family to join you.