WITH MORE EVIDENCE pointing to the benefits of brief, intense workouts, the much maligned ROM (Range of Motion) cross-trainer is back—16 years after its debut. The ROM combines features of a rowing machine and stair climber—as conceived by the Marquis de Sade—and was created to replace tedious hours of weight lifting, cardio work, and stretching with a daily four-minute workout. Despite the naysayers who can't believe four minutes qualifies as a workout, ROM inventor Alf Temme has retained his Panglossian faith in his machine.

"The ROM is not pleasurable," says Temme. "But you do it because you get the darn workout over in four minutes." How? The ROM demands your full range of motion, engaging 12 times the number of muscles you'd use on a treadmill. Curious? You can try the $14,615 machine at one of 20 exercise facilities across the country.

Pasadena, California, chiropractor Todd Hewitt, 35, opened a ROM gym last year, charging members $89 a month. So far, he's converted everyone from soccer moms to tennis pros. "My clients come to realize that they don't have to waste valuable time on general conditioning," says Hewitt. "They're in and out of here in 12 minutes, and they can use the extra time to practice the skills it takes to improve their sports."