Gym envy is when someone tells you that they have gone to the gym or you see people training and you become jealous as you haven't been able to go. Gym envy is smoking getting trimmer whist you are getting fatter as you can't train.
Friend; I just ran 10km before work
You; listening as you look at them with hate as you had to wake up early so could'nt train. ( Gym envy)
Surfing Instagram after you've just eaten heavy meal of people doing cross fit .... Wanting to throw your phone in the bin with Gym Envy
Friend ; I got my body fat down to 11%
You; I got Gym envy , just can't get back into gym since my holiday
Friend 1; what's up with jon?
Friend 2 ; he has Gym envy as he hasn't been able to train this week... Just shut up about your training today as he is moody as he thinks he is fat!