Apple's secret workout lab could lead to a super powerful Apple Watch

Apple has a secret workout facility tucked away in a nondescript office space outside of its new HQ, where researchers are collecting reams of health data for the next generation of products, starting with the Apple Watch.  The company opened up (some of) the facility's doors to Men's Health for an inside look at the lab where Apple has tracked more activity and exercise data than any other human performance study in history — at least according to Apple director of fitness for health activit...