Must be a very large gym.
Wormholes.
This is a fun one.
He forgot his GPS
?????
I read it as he lost his footing in the gym ( and presumably fell over)
Ridiculous!
" how did he get lost walking to the gym ?" seems more natural to me, the " while" being superfluous.
Walking IN the gym, not to the gym. He's already there...
I've just realised it probably means he got lost walking on a treadmill in the gym!