Accuracy of calories burned while biking

[DarcyInOregon]

I use a Garmin Edge 705. The strap will read a low heart rate if the strap gets too loose or if the strap gets caught up in my bra band. What I do before every bike ride is after turning on the Garmin, I make sure the heart rate is showing on the display and that it shows a normal standing around fussing with the bike heart rate range, like in the 80s or 90s. If the heart rate reads lower, for example 35, then there I am out in the public, unzipping top layers and adjusting my bra and tightening up the chest strap. When the heart rate reads normal, then I put the Garmin on the bike and I am ready to go.

Most of my cycling friends use a Garmin and they are always posting links to their rides on Facebook. Over time I've seen enough Garmin data from different cyclists to know that for cyclists in my age range, male and female, our average heart rate on a ride is 120-140, depending on the elevation gain; I am age 57. Younger cyclists and/or cyclists who are not very fit may have a higher average heart rate.

I reviewed my ride history at Garmin Connect and for a ride that is 70-80 miles, my calories burned is between 2500 and 3000 and my average heart rate is around 130.

[nscrbug]

I will try some of the suggestions made here like checking my pulse to see if it matches up with the Garmin before we start. I still think that something is screwy with it. I've been working out nearly all of my life, so yeah, I'm in decent shape cardio-wise...but I still don't get that my burn is so low on bike rides. I understand that I do have to work a bit harder at it to keep my HR up, but an average HR of 108 over the course of a 4 hour ride??? Just doesn't make sense. I'm pretty sure that it's NOT me, and definitely something wrong with the Garmin unit or HRM itself. I'll have to look into this a bit deeper to see if I can come up with anything.

Thanks everyone!

Linda

[sazza]

yes defintly low. I have a garmin edge 705 today rode for 2 hrs 37 mins, 35 miles and did 1356. However I think that is too much. I never believe the calories burned on the edge as the figure seems quite high

[Crankin]

This is why I stopped using technology on my rides. I was getting obsessed with the numbers and jealous when people were higher/lower/blah, blah, blah. And, I found I was constantly looking at my monitor, which was not good.
I didn't learn anything that I already knew. 1) My HR is always higher than others of the same weight/height/age, despite the fact I have been fit for 25 years 2) At my size, it is incredibly hard to burn calories. I have to work twice as hard or ride three times as long to burn the same number of calories as someone who is of average height and heavier. Even when I was 32, weighed 90 lbs. and was teaching 7 fitness classes a week, my average HR was high during a work out. Since I don't have any cardiac issues, I assume it's just the way my body works.
So, I figure when I am breathing heavy at the top of a 15% grade, that is my cue that I am working hard. I also use my average speed or time over routes that I do all of the time to judge how my fitness progresses over the season.

[goldfinch]

There are too many variables for the Garmin to give accurate readings. It uses your heart rate and algorithms to make estimates but does not account for all variables, like percentage of body fat.

But then again, estimates of calories eaten aren't so accurate either.

Typically, these heart rate monitor estimates are high. But as others mentioned you will get a low estimate if your heart rate is artificially measured low.