Researchers are still trying to figure out the best way to analyze the data collected from wrist-worn accelerometers, but they hope to be able to accurately distinguish among many different types of activity, including sitting, standing, walking, cycling and riding in a vehicle, Troiano said.
If researchers agree on the best approach for analyzing accelerometer data, such a method could cross over to the apps used with commercial fitness trackers, Troiano said.
Changing activity guidelines Current U.S. guidelines for physical activity recommend that adults get at least 150 minutes of moderate-intensity physical activity (such as brisk walking), or 75 minutes of vigorous activity (such as running), per week.
But the guidelines don't say much about light-intensity activity, such as how much time you should spend sitting versus standing. "All we kind of say is, 'Sit less, and be active more,'" said Haskell, who was chairman of an expert panel that advised on the development of the current U.S. guidelines. That's because researchers don't have scientific data to back up any recommendations on light activity, he said.