You are correct, most machines display more calories burned than actual because they basically use only heart rate combined with individual size. Heart rate gives a poor estimate of total calories burned. You need more information coming from the body to get an accurate reading, which is we use the exerspy armband. But the main problem is that they not only exaggerate the number but also include all the calories burned during the time you are on the machine, which misleads people into thinking they burned that many MORE calories. From that perspective It would be better if they only displayed the incremental calories. Incremental calorie burn does not include calories you would already burn at rest (RMR) for the duration indicated, but only those you burn as a result of the activity. This would give you a better idea of how many extra calories you can eat to still be on goal