Inaccurate HR and Calorie Burn Estimates?

[mellemelx]

I’ve noticed that when I do a workout and wear a different HRM device, my Luxe consistently displays a lower heart rate and (related) significantly lower number of calories burned. The other HRM I wear is a chest HRM so I know those are usually much more accurate but the difference is substantial. The last workout I did the Luxe said I burned 190 calories while my other device said 325… active zone minutes were the same across devices, and *average* HR was the same, but DURING the workout I could see the difference in measured HR. What’s up with that?

[t.parker]

Calorie burn is just an estimate and different devices will give you different numbers as they will be using different formulas. It's easy to check when you get Garmin, Polar, and Suunto, pair them with the same chest strap (Fitbit can't be paired) so they receive exactly the same HR but the calories will not match. I did some tests in the past against a power meter (which is a better way of measuring energy expenditure) and Polar usually seems to undercount, Suunto shows way too many, Garmin is almost spot on. That's why calories will always be just an estimate (or even guesstimate), no device really knows how much you burn. I'm not sure how Fitbit computes calories (probably it's a proprietary equation) but you can always export the TCX file from Fitbit and check the HR against your chest strap (whichever chest strap you have, I'm sure there is a way of exporting TCX/FIT data) to see whether it has greater inaccuracies that may affect calories.

[mellemelx]

Yes I recognize that it’s an estimate. I still feel the margin of error is too large. That’s my point. 

[FlippantCactus]

I have this as well. Would be nice to see a change in this. I don’t burn 3000 calories a day, I’m idle for 70% of it and I don’t burn 150 calories an hour…

[Nicola_grec]

There is an article on internet , that testen the calorie burn on different devices, thy used some mask or so to test the acurate calories burnt during workout.

the Fitbit was the best , with a error marche of 75% , the other devices even a heartrate strap , where 65% or so . I think fitbit is correct . 

[Nicola_grec]

https://www.businessinsider.com/how-accurate-is-fitbit-calories-burned?international=true&r=US&IR=T

[mellemelx]

Perhaps this is still relevant. But perhaps not. 2017 may as well be a century ago when we are talking tech. Also on your previous comment you specifically said they compared it to chest worn monitors which is not true. It was only compared to other wrist worn monitors—which is more fair and, if the result still holds, still encouraging. I didn’t post because I expected a wrist worn monitor to be as exact as a chest worn monitor. I just felt the difference I was seeing was drastic on some occasions. 

[mellemelx]

Calories burned is a bit different because you also have to take BMR into account. Fitbit may be the best this if it uses a formula that learns about your daily activity level (as opposed to competitors which may just have you guess at your activity level range) and factors that in. Otherwise they’re all using the same data for estimates- weight, height, age, gender.