Personal monitor vs. cardio equipment monitors: accuracy?

tammywisco

Hello all,

I have a Polar heart rate monitor and for the last month I've been doing cardio exercises on various types of workout equipment, such as elliptical machines and treadmills, but I've noticed a drastic difference in the amount of calories burned between what my monitor records and the equipments' tally. Usually for an hours worth of exercise (staying in my fat-burning heart rate zone) my monitor will record between 100 to 200 calories less than what the machine will show. I can understand some variance, especially if the workout equipment doesn't allow for inputting height, age and weight, but it doesn't account for the times that I do enter my information in. The variance is important enough to address especially for those that may think they have burned more calories than actuality. It can sabotage efforts and slow weight loss.

I always err on the side of conservatism and use the information from my monitor, but just wondering if anyone else has come across this dilemma and, if so, can shed some light on it.

Much thanks!