When you have not been to the gym for an extended period of time due to laziness or any other poor excuse.
Donnie: Where you been homey, I haven't seen you in ages?
Greg : All this partying is really taking its toll. I have severe gymnesia!
Greg : All this partying is really taking its toll. I have severe gymnesia!
by Gregsands August 22, 2012
A habitual or compulsive involvement in physical exercise in a gym or fitness centre that leads to the detriment of other aspects of the individual's day to day life.
by BijomaruMogami September 01, 2017