Accuracy of calories burned while biking

[bellissima]

But it looks like all of those just take your MHR (either tested or approximated from the general population), start at 60% and divide into equal portions... Which I know how the 301 got MHR, but it's possible that's what it does for zones 2 through 5, since what it gave me for those are all equal within a beat.

I'm reasonably confident of my MHR. That's what I'll see toward the end of the fourth or fifth of a series of sprint intervals on a really hot day, about the time I'm seeing stars and ready to throw up... I'm actually more confident of that number than I am of my RHR - I've never bothered to wear a strap while I sleep, so I just took what I'll see when driving to an event, which is in the low 50s as long as traffic isn't crazy, and then just subtracted a couple of beats for the demands of attention and sitting.

But how do you actually test for the zones?

I agree, is most likely that your MHR is correct as that is the number you can see when dying onr those intervals Calculating your zones from your MHR is good. I would use your anaerobic threshold to calculate your zones as it is a more accurate, anaerobic threshold(Lactate threshold) is the point at which lactic acid starts to accumulate in your muscles, this will be your zone 4 and is between 80% and 90% of your maximum heart rate. You can find out your threshold with a simple test. Find a long climb or a hill that will take about 30minutes to complete when riding all out, if a hill is not available it can be done on a flat or against the wind. Warm up for at least 20 minutes and then ride as hard as you can for 30 minutes, at the 10 minute mark press the lap so it will record the last 30 minutes of you hear rate, this will be your Threshold (Lactate threshold) and you can use this test for running also. Once you get this number all the zones are calculated from that number.