A leaked memo from Apple's internal employee website offers some more information on how the company designed the health and fitness aspects of the Apple Watch.

Apple Watch

The memo, as posted by 9to5Mac, includes quotes from Apple Watch team member Jay Blahnik. He is quoted as saying the company has gone to great lengths to study how people will use the Apple Watch.

From the memo:

"We needed to study the conditions in which the device would be worn and build expertise on how to measure all-day activity and exercise. At the scale we sell our product, we couldn't just use off-the-shelf algorithms. We needed to build our own knowledge base from the ground up. In many ways, the health and fitness research and testing we have done is historic. We've studied more people, in more conditions than most university research has ever done," he says.

Blahnik also talks about the Workout and Activity apps included in the Apple Watch. Of those two, the Activity app was harder to develop:

""From day one, we wanted to build something iconic, not just another version of a pedometer. We kept asking ourselves what we could do to measure all-day activity that would be more useful than traditional all-day activity trackers?" The answer was a simple philosophy: "Sit less, move more, and get some exercise," he says. "That became the guiding principle we built the Activity app around."

Source: 9to5Mac