gym friend; gym buddy
Casual term for a friend one meets or trains with at the gym. Common in informal conversation and social media.
ジム友と一緒にトレーニングするのが楽しい。
It's fun to train together with my gym buddy.
新しいジム友ができて、モチベーションが上がった。
I made a new gym friend, and my motivation went up.
Abbreviation of ジム (gym) + 友 (friend). A modern casual coinage following the pattern of 飲み友, ママ友, etc.