"We spent a ton of time working with researchers at Arizona State University, measuring the motion of your wrist in a particular activity and then correlating it to oxygen intake and consumption for that activity.  Then we developed algorithms to assign NikeFuel based on each activity." 

"We launched this on January 19 in New York—and at the time, you didn't have a reference point: How much is 2,000 NikeFuel?  Through Facebook Connect and our app, users can quickly correlate their scores with other people's."