I've been using my watch since July, and was under impression that workout app is pretty reliable. Here is what happened today. I went to a pilates class, starts 12pm, started workout app "Other". I always do it. Average heartbeat 145, great! The class was 12-12:50; 1:15 I was back at work. I completely forgot to "end" the workout, so it's been running until 2:45pm. From 1:15 to 2:45 I was working at the desk, and when I looked at workout app it was showing me intense activity when I was sitting at the desk!! (see screen shots). I decided to do another test, and started another workout as "Other" at around 7:45 when I was home, sitting in my chair and watching tv - and again I see spike on the app and number of "Active" calories. What is it? How can I trust this app now? Thoughts?? Thanks -------------------------------------------- Spike at 6pm exactly - when I was actually walking home, pretty briskly, no workout app running. Spike at 7:45 is when I was actually sitting in my chair - with "Other" running, shows more activity than at 6 when I was actually walking. And here is my "workout" at 7:45 - by sitting and watching tv: I also use "Outdoor Run" when I am running, so app knows that my heartbeat is way above 100 when I am working out, in case it can think that heartbeat in 70th is the workout for me.