Apple has been using a specialized fitness lab to collect data for the Apple Watch, making sure that it can gather the most accurate readings possible.

The lab, which has now been shown to the public for the first time, includes exercise equipment, specialized rooms, and diagnostic equipment to measure exactly how the human body responds to certain conditions while working in particular ways. All of this data has helped Apple develop and fine-tune the fitness features of the Apple Watch, according to ABC News:

Apple engineers, managers and developers have been secretly volunteering for the past year in this state-of-the-art lab to participate in rowing, running, yoga and many more fitness activities in order to collect data for the Apple Watch's inner workings.

Features of the lab include climate chambers, which test how the watch works in different environments. Participants also wear specialized masks to accurately measure breathing.

Fitness has been one of Apple's major areas of focus for the Apple Watch, and it's not surprising that they developed an entire facility around precisely measuring this kind of data. The watch comes with a dedicated Activity app that measures total body movement, your separate exercise activity, and how often you stand.

Pre-orders for the Apple Watch being April 10, and the device goes on sale April 24.

Source: ABC News