英语语法分析

Exercise can produce endorphins.

运动可以产生内啡肽。

It has been suggested that regular release of endorphins increases people's longevity.

有研究表明，定期释放内啡肽可以延长寿命。

Scientists believe that this makes your muscles tiring, so we start to produce endorphins.

科学家认为这会使你的肌肉疲劳，所以我们体内开始产生内啡肽。