And the smaller the physical distance between friends, the larger the effect they had on each other's happiness.

VOA: special.2009.01.21

How many people know that three times a week physical exercise,30 minutes each time has the same effect ? as our most powerful psychiatric drugs?

多少人知道，每周三次,体育锻炼，每次三十分钟，与最强劲的精神药物,有同样的效果？

哈佛公开课 - 幸福课课程节选