The boxing bell rings and Alan Katz starts pounding away at a punching bag. After 30 seconds the bell rings again and it's off to arm curls at the next station.
In 20 minutes, he's completed a series of cardio and strength training stations that experts say is in an excellent way to stay in shape.
The Blitz in Tampa, Fla., where Katz exercises three times a week, is among the growing number of gyms promising an express circuit workout, which involves a laid-out course of about a dozen exercise stations. The concept - around for decades but popularized in the market by Curves for Women several years ago - is finding favor with the mass of Americans who say they just don't have the time to exercise.
"What's beautiful about it - you're catching everything in 20 minutes. I come out of there and I know I've done everything. It's a no-brainer," said Katz, a 47-year-old suburban Tampa resident. As a working father of two teenage girls, time is a scarce commodity.
Despite the national obsession with fitness, about 85 percent of Americans do not belong to a gym, according to the International Health, Racquet and Sportsclub Association. The most frequently cited reason for not joining a gym? A lack of time and intimidation, said Brooke Correia, the industry group's spokeswoman.
"The majority of these people are open game for the industry," Correia said.
It's no surprise that circuit workouts - cheap, low-key and easy to understand - are popping up in strip malls coast to coast. About a third of the country's estimated 30,000 health clubs are now express workout facilities, according to IHRSA. While Curves found an audience among middle-aged and older women, the spinoffs are branching out to other groups.
Cuts Fitness for Men, which opened in 2003, now has 90 locations across the country. With a tan-and-blue color scheme and "Cheers"-like camaraderie, founder John Gennaro said members are typically between 30 and 60 and often watch a baseball game together after their workouts.
The Blitz, a boxing-themed circuit gym, has 75 locations nationwide. This fall, president Scott Smith is planning a foray into the 18 to 35 market with a coed, military-themed version called "Commandos."
Even major chains like 24 Hour Fitness and Gold's Gym have rolled out circuit workouts.
One circuit gym in southern California invites the entire family to work out. At Family Fitness Express in LaCanada, Calif., members are encouraged to bring along the kids, or even grandma and grandpa.
"It's a great first step into fitness. And it's a whole lot better than sitting at home and watching TV," said Richard Cotton, spokesman for the American Council on Exercise.
The appeal of a circuit workout is easy to understand. The cost is typically between $20 to $40 for a monthly membership. For those who have never stepped foot in a gym before, the routine takes the guess work out of exercise.
"If I walked into a gym, I wouldn't know what to do. This makes sure you get each muscle group," said Christy Cramer-Barry, who frequents Tone & Fit, an express workout for women that opened last year in Albany, N.Y.
The 36-year-old signed up for a gym membership once "years and years ago," but never ended up going. At Tone & Fit, she feels comfortable among the women who dress comfortably and aren't interested in showboating.
"This is the first time in my life I've exercised," Cramer-Barry said.
For others, the appeal is promise of efficiency.
With two teenager, Katz said it was always too easy to find an excuse not to exercise before. Now he goes to The Blitz several times a week after work.
"This gives me no excuses. I jump in and out. If I can stay longer, I stay longer," he said.
His wife, Judy, was so impressed with her husband's newfound dedication she joined a Curves. "And I never have to wait for a treadmill," she said.