YOU SAID:

with a spring in his step, he could run faster than a man with a turtle in his pants

INTO JAPANESE

彼は足取りが軽やかで、ズボンの中に亀を入れている男よりも速く走ることができた

BACK INTO ENGLISH

He was light on his feet and could run faster than a man with a turtle in his trousers.

INTO JAPANESE

彼は足取りが軽く、ズボンの中に亀を入れている男よりも速く走ることができた。

BACK INTO ENGLISH

He was light on his feet and could run faster than a man with a turtle in his trousers.