workoutaholic 

a person with a compulsive need to workout on a regular basis, usually daily, for a number of hours.

Tony practically lives at the gym, because he's a workoutaholic.

workoutaholic by Syed Azeem December 21, 2008

workoutoholic 

A person who is constantly exercising and has an obsessive behavior towards exercising. Often associated in gyms and with sports. May own instructional exercise tapes or discs and/or exercise equipment. Commonly identified with sweatpants, running shoes, and mp3 players. Usually very athletic and fit.

Kim works out at least five days a week; what a workoutoholic!

workoutoholic by K.J. Strawn January 11, 2008