A “gymaholic” (gym + -aholic) is someone who likes to work out in a gym. “Tall, good-looking man, 43, gymaholic” was cited in a 1988 personal advertisement in New York magazine. The word “gymaholic” has been printed on many gift items, such as posters and T-shirts.
 
       
Wiktionary: -holic
Alternative forms
-aholic, -oholic
Etymology
Back-formation from alcoholic.
Suffix
-holic
1. Denotes addiction to the substance or activity of the stem word.
 
Google Books
26 September 1988, New York magazine, “Strictly Personals,” pg. 191, col. 1 ad:
Educator, In Private Practice — Tall, good-looking man, 43, gymaholic, caring, pensive and playful. Seeks spirited, sincere, pretty woman who knows where she’s going and prefers not to make the trip alone.
 
Google Books
Is He Really a 10
By Jan-Marie Wells
Saratoga, CA: R & E Publishers, Incorporated
1991
Pg. 83:
GYMAHOLIC
He is so narcissistic about his body that there isn’t a mirror in the world that hasn’t seen him admire himself. Going to the gym three days a week for an hour is enough for a man to stay in shape
     
Google News Archive
22 December 2002, The Blade (Toledo, OH),  “Phantom,” pg. F2, col. 2:
“There are quite a few of us who are gym-aholics, so that’s one of the first things we find, a local gym that we would be able to join.”
(Ted Keegan.—ed.)
   
IronMag Forums 
OMNIFEX
05-06-2004, 09:21 PM
Are You A Gymaholic?
I’m a Gymaholic, and, proud to say it
I workout 6 days a week.
 
Twitter
Grace Smith
‏@gracesmith
@nicolablack Go for it! Im a gymaholic now, its tough to beat the feeling of a good workout, fitness here i come 😉
10:58 AM - 21 May 2008
 
Urban Dictionary
gymaholic
Someone who goes to gym and work out on their basic routine. Someone who wants to stay fit.
I AM A GYMAHOLIC.
by Papu September 17, 2013
 
(Trademark)
Word Mark GYMAHOLIC
Goods and Services IC 025. US 022 039. G & S: Hats; Jogging suits; Shorts; Sweat bands; Sweatshirts; T-shirts; Tank tops; Tracksuits; Vests
IC 045. US 100 101. G & S: Online social networking services in the field of fitness
Standard Characters Claimed
Mark Drawing Code (4) STANDARD CHARACTER MARK
Serial Number 86551388
Filing Date March 3, 2015
Current Basis 1B
Original Filing Basis 1B
Owner (APPLICANT) Bechet, James S. INDIVIDUAL FRANCE 705, King Street, Apt 1708 Toronto CANADA
Type of Mark TRADEMARK. SERVICE MARK
Register PRINCIPAL
Live/Dead Indicator LIVE