Depending on the age and gender too, an average person in the 30's can burn 70-80 colories per hour while sleeping. That's about right for someone who is sleeping for just over 8hrs. My guess is HRM may not be set correctly. I've been thinking about getting that HRM.treksngiants said:Just bought a polar hrm. I wore it to bed last night to get a RHR. It told me that I had burned 675 calories while sleeping 6.5 hrs. Is that possible? I weight 178lbs. height 6'0. RHR 62.