One big thing exercise does is it raises your levels of brain derived neurotrophic factor — BDNF.

锻炼的一个很大的作用就是，它能提高你脑源性神经营养因子的水平。

Protect yourself and your brain from stress, you release this protein known as BDNF, brain derived neurotrophic factor.

为了在这种压力下保护你自己及你的大脑, 你会释放出这种被称为BDNF的蛋白质, 大脑衍生出的神经营养因子。