YOU SAID:

i be up in the gym just working on my fitness

INTO JAPANESE

私はちょうど私のフィットネスに取り組んでいるジムにいる

BACK INTO ENGLISH

I am just in the gym working on my fitness

INTO JAPANESE

私はちょうど私のフィットネスに取り組んでいるジムにいます

BACK INTO ENGLISH

I am just in the gym working on my fitness