Accuracy of calories burned while biking

[OakLeaf]

When the battery in my HR strap is getting low, it'll read low. I need to replace mine right now, actually ... about halfway through this morning's run the readout dropped by about 70 bpm.

I think setting your HR zones correctly has a lot to do with the accuracy of the calorie reading as well, but I have no idea how to do that manually. The old Garmins (like my 301) had an algorithm that would figure zones for running. I suppose they must not have been that accurate, or they would've brought that feature forward into the newer models, but it really seemed to track my perceived exertion well. I just carried those zones over into later versions of GTC, and into the cycling side, even though I know that MHR for cycling is lower than running.


ETA - to AZfiddle, the 305 doesn't use the HR based calorie computations. For running it doesn't make that much of a difference, but for cycling it's huge. Three hundred calories per hour is probably ballpark for most women cycling at average effort. Five hundred maybe if you're solo, in a headwind, or on the ascending side of a mountain...