Instead of reinventing the wheel, equipment manufacturers typically take an existing technology and make it more interactive through various computer, video and ergonomic enhancements. The standard workout article typically presents a muscle-building routine and an aerobic workout, then explains how to combine both into a complete training regimen. Equal but separate, to turn an ignominious phrase on its head. But what if muscle building and aerobics could be pursued simultaneously in one session? Competitive bodybuilders could use it precontest to get cut without losing muscle mass, or cycle it into their off-season training to increase their strength. Hardcore ironheads who train till they drop could get there fast following such a double-barreled approach, while fitness competitors could get a full-body workout and burn a ton of calories at the same time.

When it comes to selecting a class, this person identifies two particularly important variables: an instructor’s personality and his or her selection of music. “The music really helps make it fun,” she says. “If you like the teacher’s personality and choice of music, chances are you’ll hang in there; if you don’t, you’ll probably have a hard time sticking with it.” Any gym offering aerobics classes should be able to explain which ones most closely meet your own needs and interests. VIRTUAL REALITY OR VIRTUAL WORKOUT? Just as the world of aerobics classes has grown increasingly diverse and sophisticated in the ’90s, cardio exercise machines have become more elaborate in recent years.

To build some muscle while doing your cardio, try circuit-training and body-sculpting classes that roll resistance and aerobic training into one continuous routine. That’s just the tip of the iceberg. None of these types of classes is inherently better or worse than others; it depends on where you’ve been and where you want to go. “If you used to run track or play basketball, you should probably try something like a high-low class, which entails a lot of running and jumping,” she explains. “On the other hand, if you aren’t a dancer or a ‘movement’ person, I wouldn’t recommend a funk or a hip-hop class, at least not initially. It’d be confusing and you probably wouldn’t get a good workout.”