Step Aerobics Goes Double for This Class : Two platforms are lined up parallel for a workout that, its originators say, is twice as challenging and offers more variety.

When a certain group in South Orange County gathers twice a week to do the two-step, the dancers are wearing sneakers, not cowboy boots.

Their choice of footwear is not only practical, but essential. In this part of San Juan Capistrano, you might say it’s a two-step of a different color.

In the class at the Marbella Golf & Country Club, where it originated, it’s called the “Double Step,” something the fitness staff created to challenge its most physically fit members.

The instructors say their variation results in a routine that is twice as challenging as those used in other classes, in which exercisers will climb up and down on a single eight-inch platform.

The idea is that the two steps will maximize the effects of a step workout and also allow for more interesting choreography, Marbella fitness director Kristi Hugstad said.

For the double step, two steps are lined up parallel with a space of about one foot between them.

“Both the single and double-step classes work all muscle groups,” Hugstad said. “But when you use two steps, you double your workout area. Since you have more space to cover, you’re using a greater range of motion and working your leg muscles more intensely. This elevates the heart rate, making the workout more strenuous.”

No one has suffered from any injuries since the class began, the instructors say.

The classes are two hours long, one hour for the step aerobics and one for other floor exercises.

Since Marbella put the double-step class into its program about four months ago, Hugstad said, instructors from nearby gyms and health clubs have shown interest in learning the technique for their own programs.

Stella Prenovost, fitness director at the San Juan Creek Health Club in San Juan Capistrano, said Marbella instructor Beth Sanden brought the idea to her club, where she also teaches and where it was an immediate hit.

“People were ready for some type of variety, and she offers that,” Prenovost said.

The instructors warn, however, that the movements involved are not designed for the novice stepper. All agree that it’s hard work--no matter how easy those polished steppers might make it look.

“I have total concentration in that class . . . . I’ve never been in a class like that before,” said Jackie VanKatwyk of Dana Point.

“You definitely have to be in tune to your body when you have the two-step.”

The only drawback is that in a class for just 20 people, “each participant needs two steps, and it gets crowded enough sometimes in the regular classes,” Hugstad said.