Curves has more than 8,500 locations worldwide, Anders wrote. "For every two McDonald's in the United States, there is one Curves for Women.
What is Curves?
The Curves workout is a 30-minute circuit session. Exercisers spend time on each of 12 hydraulic resistance machines, alternating between 30 seconds of lifting weights and 30 seconds of stationary jogging, marching or walking on springy recovery boards. At the end of each training session, participants are encouraged to do five minutes of stretching.
"Since its inception in 1992, more than 4 million women have joined the 30-minute circuit training fitness centers. The Guinness Book of World Records lists Curves for Women as the world's largest fitness center franchise," Anders said.
"Curves tapped into a huge untouched market -- masses of inactive, middle-aged women intimidated by the health club scenario or scared away by a bad experience -- and offered them a friendlier and more comfortable exercise option."
What self-respecting fitness professional wouldn't applaud that kind of effort?
But does Curves for Women really work?
And if so, who does it help? What sort of exercise intensity and calorie burn can women expect from such a workout?
The detailed results of the study, funded solely by one of the most prestigious and highly visible organizations in the fitness industry, the American Council on Exercise (ACE), is available at the "Get Fit" section of the ACE Web site -- www.acefitness.org/getfit -- and clicking on "research and studies."
To conduct the study, ACE enlisted the expertise of Kristin Greany and John Porcari, researchers at the La Crosse Exercise and Health Program of the University of Wisconsin, La Crosse.
The researchers recruited 15 healthy women from two Curves locations in La Crosse. All subjects were between the ages of 26 and 55; the average age was 42.
Prior to testing, treadmill assessments were conducted to determine each subject's aerobic endurance level. During the test, a portable metabolic analyzer measured oxygen consumption and calories burned. Heart rate also was recorded, and ratings of perceived exertion were assessed.
Researchers found that "The Curves workout is a good time-efficient, low-to-moderate-intensity exercise program for those who have been sedentary or for that segment of the population that likes a non-intimidating environment for exercise," Greany said.
It works, but ...
"Their no-frills, nurturing, half-hour approach to fitness works."
The researchers learned, however, that 30 minutes of stop-and-go circuit training does not burn up a lot of calories.
As a result of their metabolic calculations, Greany and Porcari reported the 30-minute circuit routine burned an average of 184 calories.
"Intensity-wise, it's similar to walking four miles an hour on a treadmill for 30 minutes," Greany said.
"People may be surprised by the relatively low average total caloric expenditure of the 30-minute circuit workout," Porcari said. The data may serve as kind of a wake-up call that half a Krispy Kreme donut is all that it takes to negate the (calorie-burning) effect of a Curves workout."
Despite this bad news, there's plenty of good to report when it comes to fitness benefits of following the Curves routine.
Greany and Porcari reported the Curves exercisers got their heart rates up into their training range for exercise, which put them into the threshold required for improving aerobic capacity. Greany also believes the exercisers' upper and lower body and core strength improved.
In the final analysis, there are better, more intense workouts available. But the founders of Curves for Women deserve credit for developing a program that has motivated an extremely inactive segment of the population to start exercising. It's this group that has the most to gain from a fitness program.
John Bobalik is an exercise physiologist and coordinator of Purdue University Calumet's Fitness Center. Contact him at firstname.lastname@example.org.