YOU SAID:

And once he starts his workout,

INTO JAPANESE

そして、ひとたびトレーニングを始めると、

BACK INTO ENGLISH

And once you start training,

INTO JAPANESE

そしてトレーニングを始めると、

BACK INTO ENGLISH

And when you start training,

INTO JAPANESE

そしてトレーニングを始めると、

BACK INTO ENGLISH

And when you start training,