I was hoping someone could shed some light on this topic because it’s been bugging me. I cannot seem to figure it out. I am 5’6, 169 lbs and 48 yrs. My resting heart rate is 54. I’ve done over 250 spin classes and I wear a heart rate monitor and use the FITIV app each time. I average a minimum of 100 calories per 10 min of spinning. As of last Sunday, the calorie count of any exercise I do, including spinning burns significantly fewer calories (at least 1/3 less). I checked everything and nothing has changed in account. I tried a different monitor. Still, same results. Does anyone have any insight as to why this is happening?