This is interesting, and I think you're on to something. I got a fitbit when I got serious about running because I had no idea what it felt like to run in zone

This is interesting, and I think you're on to something. I got a fitbit when I got serious about running because I had no idea what it felt like to run in zone 2. I can read about it, but that only gets you so far. While running I could actively check my heartrate and adjust. A year into the hobby and now I don't bring my fitbit on probably 50% of my runs. I know how fast I need to go.