Calories? Can this be right?

[dbrouse]

I did a 64 mile ride on Sunday:

Dist: 64.18 mi (4:20:51)
Energy: 1574.9 kJ
Cals Burn: 1505.7 kcal
Climbing: 2128 ft
Braking: -169.3 kJ (-10.7%)

My Garmin Edge 500 calculated 4800 calories. H-U-G-E difference. Can anyone shed any light on which is more accurate. I've attached the iBike file if that helps

Thanks in advance!

[racerfern]

Sounds about right for the iBike. Longer rides should burn about 400-500 kcal/hr. Maybe 550 tops. Of course there are exceptions but there's your ballpark. The Garmin devices are notorious for over estimating calories. I weigh 179 lb. and I have my Garmin 705 set to 79lb, that way the calorie estimation is reasonably close.

[rruff]

If your iBike is calibrated properly, it will give a good estimation of calories. Calories = power*time/efficiency... with only the efficiency being estimated, and it doesn't vary that much. The Garmin is a WAG.

[rcmaps]

I have a Sigma Rox that also estimates calories based on average heart rate and weight of rider etc. I have noticed on the initial rides using both systems that Sigma slightly over estimates calories compared to iBike.

I'd tend to rely on the iBike as it's a more direct measure of power rather than using heart rate to estimate calories.

And yes, I have heard too that Garmin is notorious for overestimating this.