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What's Behind the Women-Only Fitness Center Boom?

The evidence can be seen at nearly any strip mall: A female-only, time-efficient circuit training exercise concept is striking a popular chord.

Curves for Women, a Waco, Texas-based fitness franchiser, was the first to market the concept. Almost 5,000 Curves studios are now in operation. The Curves International, Inc, Web site notes that the company aspires to the Wal-Mart-style concept of widespread coverage, particularly in suburban and rural areas. Since the first Curves studio opened in 1995, other fitness centers have emulated Curves' approach.

What's Inside a Curves Studio?

Curves studios are small and have few frills—such as changing rooms but not showers—and more limited hours, as compared with traditional health clubs. The streamlined offerings keep fees low; according to Curves, customers pay a one-time initiation fee ($49 to $74), and a monthly fee of $29.

The exercise program consists of hydraulic weight machines interspersed with stations where exercisers perform stationary aerobic exercise, such as marching in place or calisthenics, before progressing to the next eight or more hydraulic weight stations. Members exercise for 30 seconds at each spot prompted by a voice recording and music; they complete three circuits within the 30-minute workout.

The hydraulic weight stations were designed by Curves founder and chief executive officer Gary Heavin. They are sized for women, and the hydraulic system means exercises push against their own strength limit. No weight adjustments are needed between users, which is another feature that helps keep workouts around 30 minutes.

Another aspect of the Curves program is a structured nutrition program based on a book by Heavin, who has been a health and nutritional counselor for 27 years. (The title of the book is Permanent Results Without Permanent Dieting, Curves International, Inc, 2002.)

Though men can't legally be excluded from becoming members, they are told that other health club options could better meet their needs.

Medical Issues

Heavin says each Curves franchisee is equipped with the training and resources needed to address customers' exercise-related medical concerns. He notes that before customers begin the program, they must complete a health history form that was designed by the American Council on Exercise (ACE).

Curves, Inc requires that all primary employees be certified in cardiopulmonary resuscitation. "They receive 5 days of intensive training at our Club Camp in Waco," he says. "Additional training includes a Curves mentor who supervises the first 4 days of operation at each location."

The average age of the Curves customer is 55, Heavin says, so Curves employees are prepared to modify the exercise program if a member has a medical condition such as hypertension or osteoarthritis. "Each consultant receives training from an exercise physiologist in special popu-lation needs," he says. Hydraulic resistance exercise is inherently safe for nearly everyone, Heavin notes.

Exercise and weight loss goals are set at the first visit, and progress is measured monthly via weigh-ins, body fat percentage measurements, and tape measurements.

Good for Beginners

In his role as chief exercise physiologist for ACE, Cedric Bryant, PhD, evaluates fitness programs and exercise equipment. He says that the Curves program is a nice introduction to exercise for beginning exercisers. "They are attracting large numbers of people who wouldn't be exercising otherwise," he says.

A strength program based on hydraulic resistance has benefits and drawbacks, says Bryant. "People stay in their comfort zone, and that can be limiting." Because there is little eccentric load associated with hydraulic resistance, exercisers are less likely to develop delayed-onset muscle soreness. "For new exercisers, that's quite a benefit. Women often avoid strength training because they don't want significant soreness." On the other hand, Bryant says eccentric load is the optimal stimulus for building connective tissue. "Hydraulic resistance is not as great as traditional strength training in terms of building muscle and promoting bone health," he says.

Bryant advises physicians to encourage patients to describe their exercise experiences, whatever the setting. "Make sure they note any discomfort or unusual pain."

Why Women-Only Approach?

Heavin says women seem to be more likely to exercise if the environment is comfortable, nonthreatening, and supportive. "Our exercise system is designed to meet the specific needs of women, such as the size of the machines and the body parts emphasis," he says.

Bryant says he doesn't see any down side to women flocking to women-only exercise studios. "There's a social component there, and women are experiencing some reasonable results," he says. "Anything that can create an environment that's more comfortable—I have a hard time saying that's not a positive thing."

Lisa Schnirring

Soda Pop: An Athlete's Friend or Foe?

Some high school coaches in Minnesota are pulling the plug on soda pop machines, hoping the move will improve the health and performance of their athletes.

According to a recent article in the Minneapolis StarTribune,1 some coaches also give antisoda speeches at the beginning of the season and are keeping soda off the menu at team events. Some coaches believe the carbonation can cause stomach cramps, and others tell players that drinking soda is a poor hydration strategy.

A Sports Nutritionist's View

Nancy Clark, MS, RD, director of Nutrition Services at SportsMedicine Associates in the Boston area, says the coaches' concerns are legitimate, in some respects, because eliminating soda promotes a healthy diet. "You need to fuel your body with premium nutrition with quality calories. Physiologically, fluid and carbohydrates are what the body wants, and soda can serve that purpose," she says.

The worst aspect of soda pop is the excess calories, she says. She estimates that 8 oz of soda contains about 100 kcal, almost G cup of refined sugar with no vitamins or minerals. "It's unlikely to hurt performance as a preexercise or recovery drink," she says. Carbonation has never been scientifically shown to cause stomach cramps. "The carbon dioxide diffuses, but it can make you burpy," says Clark.

"You have to look at what soft drinks are displacing, perhaps a juicy apple or orange," she says. "Soft drinks are a concern when they are replacing wholesome, healthier food."

What About Caffeine?

Scott Paluska, MD, assistant professor in the department of family medicine at the University of Washington in Seattle, says that caffeine intake isn't the most compelling reason to discourage soda consumption. "I think the concern relates more to the consumption of free calories from soda," he says.

The amount of caffeine in a typical soft drink is roughly half that in a cup of coffee. (A 12-oz serving of Coca Cola contains about 46 mg of caffeine. For comparison, he says a cup of coffee contains about 100 mg.) Some brands of soda and caffeinated water may contain much more, and a large Big Gulp drink may have 200 mg of caffeine, Paluska says.

While moderate caffeine intake can help performance in endurance and power events, side effects from excessive intake (greater than 6 to 7 mg/kg, the equivalent of 4 to 5 cups of coffee within 1 hour for a 70-kg man) can hurt performance. Paluska says that the role of caffeine in dehydration is unclear, but it appears that moderate caffeine consumption will not negatively affect hydration status.

Paluska says that it's unlikely that drinking excess caffeinated soda would cause an athlete to test positive for ergogenic caffeine use. The International Olympic Committee (IOC) limit is 12 µg/mL, and the National Collegiate Athletic Association limit is 15 µg/mL. "Most people who exceed the IOC limit likely have taken caffeine by some other means, such as a suppository," Paluska says.


Shah A: Student athletes told to give up pop. Available at Accessed October 7, 2002

Field Notes

Skateboard Injuries Double

The rate of skateboard injuries is increasing more quickly than the number of new entrants to the sport, according to researchers at The Children's Hospital of Philadelphia. Their report, published in the October issue of the Journal of Trauma, showed that the rate of skateboard injuries doubled between 1993 and 1998.

The authors noted that changes in skateboarding could be responsible for the increased injury rate. In the 1980s, skateboarding style was known as "vert," which used 10-ft-high ramps; however, in the 1990s the sport made the transition to "street skating," using lower ramps and increasingly complex stunts and tricks that encourage participants to skateboard in the streets.

Because injury patterns in skateboarding mirror those of in-line skating, the authors advise skateboarders to prevent injuries by using the same protective gear that in-line skaters use: wrist guards, helmets, and elbow and knee pads. They also recommend the development of skateboarding parks to discourage skating in the street and close adult supervision of skateboarders who are younger than 10 years old.

The study was based on data from the US Consumer Product Safety Commission's National Electronic Injury Surveillance System. Compared with other sports, the rate of emergency-department-treated skateboard injuries was twice as high as in-line skating, but only half as high as basketball injuries.