I'm pretty sure it looks at heart rate. In the app, you can see a graph of heart rate over time when you log an exercise. I have the surge, not sure how the cha

I'm pretty sure it looks at heart rate. In the app, you can see a graph of heart rate over time when you log an exercise. I have the surge, not sure how the charge works. Anyway, you should really get some cardio. That heart is gonna keep you alive man. Treat it well.