(Business 2.0) – Want to have Sylvester Stallone's pecs or Jennifer Lopez's ... well, you know--but can't fit two-hour stints at the gym into your what-time-zone-is-this travel schedule? The answer is, you don't have to. Just do what the celebs themselves do. Body-weight workouts--exercises that use your own mass to provide resistance, rather than machines or dumbbells--have become all the rage in Hollywood, says Beverly Hills personal trainer Gunnar Peterson, who counts Sly and J-Lo among his clients. Yet despite the glamorous pedigree, they're perfectly suited to the unglamorous life of the road warrior, since they allow you to get in a full-body strength-and-cardio workout in half an hour or less. If you're just getting started, perform the following four-step move slowly and attempt just one set of 12 repetitions. To amp up the intensity, run through it faster and jump higher at the end, working your way up to three sets of 12 reps. -- MAGDALENA WINTER