Apple, known for keeping its product developments under the strictest of lock-and-key, gave ABC News exclusive access into its top secret health and fitness lab, where only Apple employees became test subjects for the new Apple Watch.

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.

ABC News got exclusive access to Apple’s secret fitness lab, where the company tested the fitness and health functionality of Apple Watch and iOS for years. I needed to watch the video with a VPN (ABC is regionally restricted to the U.S.; YouTube version embedded below), and it was worth it: Apple has set up an entire facility with equipment and machinery worth millions of dollars to accurately calculate calorie burn and the response of the human body to various conditions – this includes special climate chambers, breathing masks, and even yoga tests.

This is impressive, and it reinforces the idea that health and fitness are going to be a big deal for Apple going forward. The video makes me even more excited about the potential of Apple Watch as a daily fitness companion.