That's because there are 10,000 Curves fitness clubs globally. Curves is the number-one fitness franchise (Entrepreneur Franchise 500, 2006) and the ninth-largest franchise in the world (Franchise Times, 2006—see also the graphic below).

Everything about Curves screams lifestyle brand. But while other faddish lifestyle brands come and go, Curves has flourished for 15 years. One reason might be that Curves capitalizes on the community of women, especially those over 35 years of age.

Curves is a fitness club exclusively for women who want to make exercise part of a busy schedule. Its concept is simple: provide a 30-minute fitness regimen combining strength training and sustained cardiovascular activity in a comfortable, supportive environment. Women exercise in a circle, using a variety of hydraulic resistance equipment and frequently moving from one station to another. The workout includes aerobic exercise and stretching.

It may sound like just another gym, but Curves is something else entirely. How many gyms offer their own magazine (and one that is more than just a glorified flyer)? Curves publishes the slick diane magazine (named after one of the co-founders) and distributes it free to its members. How many gyms have a travel service? Curves Travel offers special deals on vacation packages and cruises as a free, members-only service.

From the beginning, founder Gary Heavin envisioned a gym for women. His first venture, Women's World of Fitness, was the more traditional, large exercise facility with a lot more equipment and high overhead. When Heavin tried expanding too quickly, the business went bankrupt.

Heavin learned from his mistakes. It was 1992 and women with careers and children were clamoring for a more healthy lifestyle. Along with his wife Diane, Gary Heavin formulated a new idea targeting this audience. They decided to create a program based on a simple, easy fitness circuit for women who didn't have a lot of time to spend in a gym. They matched the facility to the program, keeping the physical space small, the equipment to a minimum, and the hours limited to daytime use.

Diane, who had a background in advertising, came up with the name "Curves." The couple opened a storefront location in the Texas town where they lived. It proved to be popular, so they opened a second Curves location two years later.

It might have ended there had Gary not determined that his personal mission was to help as many women as possible to stay fit and healthy. In an October 2006 Inc. article entitled "Gary Heavin Is on a Mission From God," Heavin says that, during a talk to a group of women, he thought about his mother, who had died at the age of 40 from obesity and high blood pressure. Certain that she would have lived longer had she been fit, he then decided that he wanted to help other women live healthy lives. With that in mind, he convinced his wife that the next logical step for Curves was to achieve critical mass through franchising.

By 1996, four years after the first Curves opened, the company had over 40 franchise locations. In 1999, Curves opened a location in Canada, its first outside the United States. By the end of 2002, Curves had opened its 5,000th location. Curves currently has 10,000 locations worldwide, with over 7,800 of them in the US. The company says there are about 1.5 Curves franchises for every two McDonald's restaurants in the US.

One reason for the explosive growth rate is the fact that Curves is very much a local community brand. The company says a Curves franchise can operate in a space as small as 1,000 square feet. Because the space and equipment requirements are modest, a Curves franchise can be successful with a relatively small investment. Curves keeps its franchise fees low to encourage expansion. That's why it is not unusual to find a Curves club even in a town of fewer than 10,000 residents.

Competition has been fierce ever since Curves first created a market for "express fitness" for women. Direct competitors, such as Butterfly Life (1,500 locations worldwide) and Ladies Workout Express, run by Lady of America (600 locations worldwide), each appropriated Curves' 30-minute workout concept and added its own spin. Butterfly Life, for example, uses specially designed equipment and employs what it calls a "360-degree approach" to women's health. You could also consider such traditional operations as Bally Total Fitness and Gold's Gym as competitors, but they are of the full-service fitness variety. Several of these gyms now offer Curves-like fitness circuits, and many have programs especially for women.

As a brand, though, Curves is very sure of itself. Its soft, cursive logo has a high recognition factor among its target audience. The logo appears on a wide range of merchandise—water bottles, t-shirts, and the like—that sells exclusively at Curves locations. The branded merchandise alone is reportedly a US$ 25 million business.

While Curves achieved its early awareness largely through word of mouth, it has had its share of success with advertising as well. In 2004, the company won a gold "Effie," awarded by the American Marketing Association, for its advertising campaign, "The Power to Amaze."

"The McDonald's of Fitness," as Curves has been called, will likely continue on an upward curve. Curves continues to add franchise locations, especially outside the US, and develop new offerings, such as vitamin supplements and the "Curves 6 Week Solution," a weight management plan. Curves knows its target audience very well—and its audience knows Curves. From a branding perspective, that is very fitting.

Barry Silverstein has been a frequent brandchannel contributor since 2007. He has thirty years of advertising and marketing experience and is currently a freelance writer and marketing consultant. He founded and ran his own direct marketing agency and held executive positions with Epsilon, a leading database marketing firm and Arnold, a major ad agency. Silverstein is the author of three marketing books, including the McGraw-Hill book, The Breakaway Brand, which he co-authored with Arnold CEO Fran Kelly.