Accuracy of calories burned while biking

[Bike Chick]

Linda, I just caught this thread but wanted you to know that I have a Garmin 500 and I have been having the same issue. We time trial on Tuesday evenings and without the hrm the Garmin says I burn around 550 calories in a 10 mile hilly tt with an 18 mph average (which I think is close to accurate); with the hrm the Garmin says I burn 225--usually cuts it in half. DH has a Garmin Edge 305 and his heart rate records in the 500-600 range for the same tt. I think it has something to do with the Garmin 500.

[Catrin]

I do not have a Garmin but have heard from others that the Garmin 500 does seem to be prone to reporting lower heart rates and under-estimating calorie useage.

[OakLeaf]

I'd suggest stopping at the top of that killer hill and taking a manual pulse.

[Velocivixen]

To original poster: Why do you want this information? Training purposes? To gauge how much to eat? Just for kicks? Numbers nerd? I'm curious.

I use a Polar FT40 to see my calorie burn for every activity (fitness) I do. I don't eat more or less based on calorie burn. For me it just ensures that I get consistent calorie burn each week for fitness.

[bellissima]

Linda,

It appears that your zones are off on the Garmin and is as you are always riding zone 1. As OakLeaf sudjested measure your pulse at the top of that hill and compare the 2 if they agree set your zones and MHR to that number.

[nscrbug]

Linda,

It appears that your zones are off on the Garmin and is as you are always riding zone 1. As OakLeaf sudjested measure your pulse at the top of that hill and compare the 2 if they agree set your zones and MHR to that number.

Yes, it does appear that I never seem to get out of Zone 1, but for a few exceptions.

I am a little confused regarding your suggestions. So are you saying that I should lower my MHR to what it is after I climb a steep hill...instead of setting it at 176 (220 - 44)? If I got that right, then my MHR would end up being like 135...which seems awfully low. Can you explain a bit more?

Linda

[bellissima]

Yes, it does appear that I never seem to get out of Zone 1, but for a few exceptions.

I am a little confused regarding your suggestions. So are you saying that I should lower my MHR to what it is after I climb a steep hill...instead of setting it at 176 (220 - 44)? If I got that right, then my MHR would end up being like 135...which seems awfully low. Can you explain a bit more?

Linda

Linda, the 220-age doesn't work with everybody and it is meat to be a starting point. As an example I am 35 and my actual MHR is 195 and I've seen higher. if I use the formula 22-35 my MHR would be 185 and that is over 10 counts off on the other hand my friend is 42, his MHR from recorded races is 193, if we use 220-42= 178 also that is 15 counts off. At this point I would suggest to set your MHR at 135 and see if you get more realistic numbers. Also do another effort on that hill and try to measure your pulse to see if it is in line with your Garmin reading.

[nscrbug]

To original poster: Why do you want this information? Training purposes? To gauge how much to eat? Just for kicks? Numbers nerd? I'm curious.

I'd have to say, "all of the above" as my answer. But mainly to gauge how many calories I need to consume in a day and how much activity I need to do. Ideally, I would like to lose a few pounds, but knowing these numbers will help to ensure that I won't GAIN any.

Linda

[nscrbug]

I do not have a Garmin but have heard from others that the Garmin 500 does seem to be prone to reporting lower heart rates and under-estimating calorie useage.

Based on what Bike_Chick posted above, I'm starting to believe this myself.

[nscrbug]

Linda, I just caught this thread but wanted you to know that I have a Garmin 500 and I have been having the same issue. We time trial on Tuesday evenings and without the hrm the Garmin says I burn around 550 calories in a 10 mile hilly tt with an 18 mph average (which I think is close to accurate); with the hrm the Garmin says I burn 225--usually cuts it in half. DH has a Garmin Edge 305 and his heart rate records in the 500-600 range for the same tt. I think it has something to do with the Garmin 500.

THIS!!! The first few times that I used the 500, I actually forgot to wear the HRM. Yet the calorie burn that was calculated for those rides, was nearly double what it is on rides when I DO wear the HRM.

Linda