I think the point is that—as the article points out—it is a lifestyle gadget, not a medical device. I think that you have to infer that it is intended to meet the training needs of people within a standard deviation of the norm—I’m thinking at the outset that training at 160 bpm probably puts you outside a standard…

Indeed, it speeds up and slows down when I speed up and slow down. I could care less what my heart rate is at, I want to know how much of my day I actually spent at an elevated heart rate. Likewise, for sleep tracking, I could care less on how accurate it is, I care about how precise it is. Say it is off by 50%, but…