Until recently, I didn’t know a thing about how my roughly 25-minute bike commute across San Francisco—or any other part of my day, really—affects my body, other than that I inevitably arrive at work sweaty and a bit out of breath when I’m in a big rush. How high is my heart rate? Do my sleep habits affect it? How many calories do I burn?
These questions have been on my mind as a number of activity trackers and smart watches have hit store shelves over the past couple of years, promising to track information like steps, sleep, heart rate, sun exposure, and calories. With one of these sensor-filled gadgets on my wrist, surely I could get accurate information about my body.
