Entrepreneur magazine said in its profile of Anytime Fitness that its locations are "small and unintimidating, and they don't seem to breed cliques of muscleheads or Zumba moms. It's the closest thing to having a basement gym of one's own."

Runyon told the magazine that Anytime Fitness could eventually support 4,500 clubs in the U.S. and 10,000 clubs worldwide.

Other fitness franchise companies on the 2013 Franchise 500 list are Jazzercize, Carlsbad, CA (No. 27); Snap Fitness, Chanhassen, MN (No. 35); Planet Fitness, Newington, NH (No. 74); Gold's Gym International, Irving, TX (No. 192); Get in Shape for Women, Needham, MA (No. 213); Tiger Rock Martial Arts International, Pensacola, FL (No. 257); RetroFitness, Colts Neck, NJ (No. 270); My Gym Children's Fitness Center, Sherman Oaks, CA (No. 358); Great Play Children's Gyms (No. 386); The Little Gym, Scottsdale, AZ (No. 393); Baby Boot Camp/Karna Fitness (No. 407); 9Round, Greenville, SC (No. 443); Koko FitClub LLC, Rockland, MA (No. 455); LA Boxing Franchise Corp., Santa Ana, CA (No. 469); and CKO Kickboxing, Hoboken, NJ (No. 482).

The magazine has yet to release its specialty categories for 2013, such as home-based, low-cost, top new, fast-growing and top global.

Only franchise companies that sent full Franchise Disclosure Documents (FDDs) or Canadian Disclosure Documents and whose information was verified by Entrepreneur could receive a listing in the magazine. To be eligible for the list, a franchise company must have a minimum of 10 units with at least one based in the United States, must be seeking new franchisees in the United States and cannot be in Chapter 11 at the time the ranking is compiled.

All companies are judged by objective measures of a franchise operation, regardless of size, according to Entrepreneur. Financial strength and stability, growth rate and size of the system are the most important factors that the magazine takes into consideration. Other criteria include start-up costs, litigation, percentage of terminations and whether the company provides financing.