Being able to monitor my heart rate without a device strapped on my chest sounded like a great idea......and this device allows you to do that, in theory. I have used both a Polar and Nike heart rate monitor in the past and the only draw back was the chest strap that I always seemed to forget at home. Well, you have no chest strap and you can monitor your heart rate while you exercise, but you have to be able to run/cycle/lift weights while placing your fingers on the 2 sensors on the watch. Quite a feat if you are at the height of your workout and don't want to stop. I found that to be a real pain when all I wanted to do was run/cycle/lift weights and occasionally look at a display to see my heart rate. I bought the device without clearly understanding how it operated.