a term describing those - mainly women- who have an unhealthy obsession with going to the gym and pounding it out for hours, despite not needing to as they are already slim. Similar to that of tanorexia, however sun beds/fake tan are replaced with going to the gym.
she's a bit of a gymorexic.
A gymorexic is someone that will eat whatever they desire with no regard to the nutritional content and rationalize it by going to the gym later and engaging in hours of strenuous exercise to "work off" overindulgences in food.
Kellie ate 2 slices of pizza, 1 slice of cake, 5 Oreo cookies, and 2 hot dogs for lunch but thinks its not a big deal because she's going to the gym tonite...she's gymorexic.