'Good Morning America' Goes Inside Apple's Secret Apple Watch Fitness Testing Lab

ABC News this morning revealed an exclusive behind-the-scenes video of Apple's testing facility for the upcoming Apple Watch, showing off dozens of Apple employees covered in various sensor-tracking technology used to gather data for the health and fitness areas of the wearable device. Apple executives Jeff Williams and Jay Blahnik accompanied ABC on a tour of the facility.

Employees of the company, from engineers to managers and developers, have volunteered to participate in the tests for nearly two years, not knowing of the reason behind the facility until recently. Wearing masks that measure changes in breathing and other various statistics, the volunteers were put through various workout regimens including rowing, yoga, and running, in order to collect data for the Watch.

“[The employees] knew they were testing something, but they didn't know it was for the Apple Watch,” said Jeff Williams, Apple’s senior vice president of operations. “We hooked them up with all the masks and so forth, but we would put on an Apple Watch covered up.”

The lab even included "climate chambers", which allowed Apple to simulate varying environments, from hot to cold, without having to physically leave Apple headquarters for testing. The company did so anyway, visiting drastically different locations around the globe to put the Watch through the most strenuous environment testing they could.

“We have traveled to Alaska and gone to Dubai to really test Apple Watch in all those environments, but we also wanted to be able to have a controlled environment here where we could see those extremes,” said Jay Blahnik, Director of Fitness and Health technologies at Apple.

“I think we've amassed already what may be one of the world's largest pieces of data on fitness,” he said. “Our view is, we're just beginning. We think there's a lot to this fitness thing...the impact on health could be profound.”

Dr. Michael McConnell, a professor in cardiovascular medicine at Stanford Medicine, told ABC News the Apple Watch has great potential to drastically change the cardiovascular technology field. He points to the ease-of-use in Apple's product to take measurements and surveys, thanks to the help of Apple's new medical-focused ResearchKit as well as HealthKit, which would offer them "a new way to do medical research."

The pre-launch buzz surrounding the Apple Watch only continues to grow as the April 10 pre-order date, and official launch on April 24, draw closer. Most recently the wearable has been spotted in numerous fitness and fashion magazines, with third-party manufacturers announcing everything from charging stands to carrying cases to secondary battery options for the wrist-worn device.

The segment, which premiered earlier this morning on Good Morning America, is a small preview for a larger piece airing tonight on Nightline at 12:35 AM ET.