The Outline:

There’s a reason why these trackers and apps are designed to be so fun, and it’s not just because it’ll make it easier to lose weight or walk more.

Every minute spent hooked up to a health device or app is a moment providing it with some very valuable data. What those companies do with that data varies wildly, but most of them are siphoning it off our wrists and selling it to the highest bidder. As a result, annoying, invasive ads might start popping up on our screens, but the consequences of this data being out there could be considerably more serious.

This tracking is exactly why I don’t use any of the apps mentioned to track whatever fitness goals I may have.