I did cardio ball for the first time. It posted that I burned 300ish calories and I had about 8 minutes left in the workout. Someone came to the door and I paused the workout to answer it; when I returned, the heart rate monitor disconnected so I reconnected it and resumed my workout. I look at my iPad and notice that calories burned jumped to 700ish. The estimated calories you are to burn is in the 600s I believe but I don't know which is accurate, especially when it practically doubles in the course of three minutes.