Should You Try These Fitness Trends?

Digital Body Monitors

The trend, explained: “Activity managers,” such as the Fitbit (fitbit.com), the BodyMedia FIT (bodymedia.com), and the Bodybugg (bodybugg.com), are worn on an arm or clipped to a belt. They use ultrasensitive movement monitors to track steps, distance, calories burned, time spent exercising, and even tossing and turning at night. (You can wear them 24/7.) They can sync with a computer or a smartphone, allowing you to log meals to compare calories consumed with calories burned and chart workout stats over time. Each gadget starts at around $100. The Bodybugg and BodyMedia FIT also require a subscription if you want more-detailed feedback, starting at $7 a month.

Expert opinion: “These devices are good for accountability, because you can see exactly where you stand in relation to your goals,” says Anderson. The BodyMedia FIT is recognized as a medical device by the U.S. Food and Drug Administration, and a 2011 study published in the journal Obesity showed that dieters who used it lost more weight than those who didn’t.

The bottom line: They’re not essential. But if you’re a goal-oriented person or like instant feedback, they can be a fun tool in your health-and-fitness arsenal.

CrossFit Workouts

The trend, explained: Think of CrossFit as a supercharged boot camp that combines high-intensity cardio and resistance training. Conducted in a class setting at CrossFit gyms (crossfit.com), a typical routine might involve swinging kettlebells, flipping tractor tires (yep, real ones), throwing weighted balls against a wall, and doing body-weight moves, such as squats (with or without dumbbells) and push-ups. Classes are usually small—5 to 20 people—and last from 20 minutes to an hour. The workout is different every time, so you don’t get bored, and fans report rapid weight loss and muscle toning.

Expert opinion: “CrossFit can be an intense workout,” says Los Angeles trainer Kristin Anderson. “You’re focusing on endurance, agility, power, and strength in one session, and all require different things from your muscles.” While you work at your own pace, the group atmosphere adds a feeling of friendly competition. However, some experts worry that this can lead to injury, especially if a person pushes herself too hard to keep up with the group.

The bottom line: If you’re already in great shape, CrossFit is a challenging way to get even fitter. Beginners should take it slow, though. Most CrossFit gyms require newbies to complete a fundamentals course before joining regular classes.