IRVINE, CA — One of the staples of Entrepreneur magazine's Franchise 500 list over the past few years has been Curves.

The women-only chain was No. 2 on the list in 2004 and 2005, No. 3 in 2006 and No. 15 in 2007. Then Curves began a downward spiral, falling to No. 185 in 2008 and all the way to No. 381 last year.

This year, Curves is nowhere to be seen on the Franchise 500 list. Curves Founder and CEO Gary Heavin says the company simply could not sustain its growth rate in the United States after reaching 10,000 locations over a decade's time.

“We've reached our potential in the U.S. market and are currently experiencing excellent growth in nearly 80 countries,” Heavin says. “We are about seven times bigger than the next largest fitness club company, which means that we are helping more women — millions worldwide — move away from illness and chronic disease. And that's what really matters.”

Despite Curves' absence, several other recognized fitness franchise companies are on this year's list. Jazzercise Inc. leads the way at No. 18, followed by Anytime Fitness (No. 43), Snap Fitness (No. 51), Gold's Gym International (No. 109), Fitness Together (No. 118), The Little Gym (No. 141), Planet Fitness (No. 157), My Gym Children's Fitness Center (No. 208), LA Boxing Franchise Corp. (No. 427) and Personal Training Institute (No. 451).

Jazzercise also is No. 5 on Entrepreneur's top 10 home-based franchise list. The Little Gym ranked No. 1 in the children's fitness category for the fourth consecutive year.

FITNESS COMPANY RANKINGS ON FRANCHISE 500 LIST

The following is a list of fitness companies that have appeared on Entrepreneur magazine's Franchise 500 list during the past three years:

2010 2009 2008
Anytime Fitness 43 47 75
Fitness Together 118 100 78
Gold's Gym 109 12 183
Jazzercise Inc. 18 42 44
My Gym 208 259 300
Planet Fitness 157 116 --
Snap Fitness 51 24 96
The Little Gym 141 126 145