gymfiltrat 

the act of infiltrating a gym.
(brooklyn-99 s1 ep14 reference)

“we gymfiltrated the gym this weekend”

gymfiltrat by zen__ March 30, 2022

Gymfiltrating 

Infiltrating a gym, most likely as an under cover cop

The police caught the smuggler thanks to the work of two undercover detectives, who were gymfiltrating the smuggler's gang

Gymfiltrating by TheJewWhoGivesChildrenSexTalks October 3, 2014