How do you say

He works out every day, and it has paid off in increased stamina over the last three months.

..in Chinese?

他每天都坚持运动,已经提高了三个月的体能。

tā měi tiān dōu jiān chí yùn dòng , yǐ jīng tí gāo le sān gè yuè de tǐ néng 。

How do you say "After three months of training, he came in first in the marathon." in Chinese?