Indoor cycling shows calories wrong

I've got my Fenix 6 connected to BikeErg. BikeErg sends cadence and watts to Fenix 6. It seems that Garmin counts only the half of calories of bekeerg2 calories. But if I only measure only the heart rate by Fenix 6 the consumed calories are pretty the same as BikeErg counts. I think there is a bug in Fenix 6 software. In Suunto the calories are almost precise compared BikeErg calories.

0 eezytiger over 4 years ago

Calories should be derived from power, not heart rate. In my experience the calculations are just fine when an accurate power meter is used.

Power x time = energy = kcal. That is measurable, not guesswork.

Heart rate based estimates are exactly that - estimates.

0 6646453 over 4 years ago in reply to eezytiger

Yes I know. But BikeErg sends the power information to Fenix 6. In my experience consumed calories are only half of the Bikerg calories. But if I use only HR in Fenix 6 consumed calories are almost the sane in Fenix 6 and BikeErg

0 eezytiger over 4 years ago in reply to 6646453

Try this power based calories calculator explanation...

https://www.welovecycling.com/wide/2020/05/14/how-to-convert-watts-into-calories-burned-on-the-bike/

Same story here - gearandgrit.com/.../

Based on my own data this is exactly what Garmin is doing.

170W average x 2.5 hours x 3.6 = 1530 Cals

0 6646453 over 4 years ago in reply to eezytiger

Yes you are correct. BikeErg exaggerates calories! Thanks!

0 eezytiger over 4 years ago in reply to 6646453

I just tried a couple of online heart rate based calculators and got results from 2250 - 2295 Cals for the same ride. A little over generous, I think.

Neither asked for my max heart rate so I can't begin to imagine how they calculated my work rate based simply on my heart rate. They did ask my age, but my max is much higher than my age might suggest, so it's probably pretty much nonsense based on population averages. People can have completely different heart rate for the same power output and completely different power output at the same heart rate. It seems an almost entirely useless metric for calories calculation.