How Fitbit Is Cashing in on the High-Tech Fitness Trend How the device manufacturer is building a following by enhancing users' workouts through gaming and community-building.

With wearable devices that track every footstep and exercise milestone, Americans are keeping tabs on their own fitness like never before. Besides offering increasingly detailed data, companies like Fitbit are enhancing users' workouts through gaming and community-building. It's an inescapable lifestyle trend--and VCs are taking notice.

Since the advent of the cubicle and the golden age of the vending machine, Americans, as has been widely noted, have been getting fatter. Some 90 million people are classified as obese, and many, many more are professional couch potatoes. The sad truth, uncovered in a study led by kinesiology researchers at the University of Tennessee, is this: The average adult takes just 5,117 steps per day--barely half the daily steps recommended by the U.S. Surgeon General.

Belying our increasing girth is our perpetual willingness to try new ways to get in shape--and these days, many of those methods are digital. In fact, the Consumer Electronics Association says the sports and fitness category is a $70 billion annual business in the U.S. alone.