HR is the same on Fitbit and Polar yet calories are off. I'm confused.

alsaxon

So I have a chest strap monitor by Polar and Fitbit Charge HR. It seems my Fitbit is underestimating calories and the Polar is more accurate, maybe overestimating by a little bit, maybe. But the Fitbit surge is like 30% off. 600 calorie workouts with polar will be 434 on Fitbit. My weight, age etc is input into both apps for accuracy. At first, I thought the HR monitor on the Fitbit was too low but at the end of each workout, my average hr and max hr are only 1 to 2 beats off. If this is the case and the Fitbit is reading hr accurately, why is it so off? I was introduced to the polar beat when I started orange fitness theory classes...the classes are a combo of treadmill, strength and rowing. I thought maybe the Fitbit could not accurately calculate the strength and rowing portion. But now I'm using both outside of class and it's still off. My usual exercise is running stairs...stopping for some squats and jumping jacks and pushups in between. I will say that I have the polar beat set to strength training as the activity, but I don't think that makes a difference, as when I was at orange fitness theory it was not set to anything in particular. In addition, the Fitbit nor the polar beat have a stair climbing default - plus I mix in other exercises while doing the stairs. Any thoughts. I know neither are perfect, but the variance is so wide that I know one of these monitors is just dead wrong.

harieta

I guess the only way you can find out which estimate is closer to the true calorie burn, you have to weigh your food, log accurately and see what happens in a month.

yarwell

Other equations are available, so part of your issue will be that the HR -> calorie maths is not the same in the two cases. Is the data requirement of both the same ? I have a Polar watch that asks for VO2max which will make it a lot more personal to me.

The other factor is "gross" vs "net" calories - is one of them deducting your BMR and the other not, perhaps. ie is it telling you the extra calories of the exercise or the total calories for the time you were exercising.

MeanderingMammal

alsaxon wrote: »

It seems my Fitbit is underestimating calories and the Polar is more accurate, maybe overestimating by a little bit, maybe.

What's leading you to assume the Polar is more accurate in terms of calorie expenditure?

Any thoughts. I know neither are perfect, but the variance is so wide that I know one of these monitors is just dead wrong.

From what you're describing as your activities, I'd suggest that both are likely to be overestimating. Regardless of the algorithms, HR isn't a reliable indicator of calorie expenditure in those scenarios.

sijomial

My usual exercise is running stairs...stopping for some squats and jumping jacks and pushups in between.

Complete lottery trying to estimate calories for that - you might just as well guess!
(That's a serious suggestion by the way.)

A more useful comparison between the two devices would be steady state cardio wearing both - then you will have an idea if they really diverge.

mgookin1

I always use the lowest number. I would rather underestimate then over estimate.