Accuracy of calories burned while biking

[marni]

I don't know anything about the Garmin Edge but those numbers seem awfully low. I use a body bugg and granted I weigh a bit more than you but I burn roughly 500 calories on an hour ride and a much slower ride at that.

I have a body bugg which is approximately accurate as long as I wear it on my ankle so the oscilator counter thingie actually works . I also wear a heart rate monitor from time to time

I think basically that it depends more on your level of fitness and the riding conditions (headwinds, hills, rough paving, stop and starts) than on anything else. I know that if I am doing a medium intensity, at at heart rate of 112- 115 bpm, (which is about 70% max for me) 15 mph ride in an average 10 mile head wind for about 1/2 of the ride distance, I will burn about 350 calories an hour.

If I push my speed to 17, get my heart rate up to 120-125 (80% max bpm ) in the same conditions, I will burn a good 400 calories an hour and if I do intervals with an occasional sprint it will go up to 500 calories an hour.

Obviously, since I am trained and prefer to ride distance and 3-4 hours at a time with no stops, my body has become efficient enough that I rarely burn more than 400-450 calories an hour. I am working on increasing cardio capacity so that I can ride faster(and hence further although that will mean coming up with some longer training rides) and at a higher heart rate and burn more calories, but I seem to be fated to be a max speed 17-18 miles an hour rider not matter how hard I ride or train. It is a little bit depressing but on the other hand, today on the elliptical trainer I managed to maintain a heart rate of 127 (85% max heart rate) for a full 60 minutes. Yay for me. By three minutes later, my heart rate was back down to 80 and at 5 minutes after the exercise ended it was back to it's normal 60 BPM.

My heart rate recovery is good and that's always good.

I just figure I do either a 300 or a 400 calorie and hour ride and plan accordingly mealwise.

I am one of those people who can eat a 500 calorie deficit daily and not lose weight, but that is a more a metabolism issue than a fitness issue. Undoubtedly some calories are sneaking in somewhere or I would be losing weight which I am not, just fighting earnestly to hold the line, but the sad fact is also that as you become better trained, your body becomes more efficient and the calorie burn decreases unless you increase intensity and or time. I am sort of at a delicately balanced point.

Anyway, do not forget to add in the miscellaneous factors, like wind, what gear are you riding in, the condition of the road, how often you stop, how long you stop, the temperature, the stress in your body and many others that I can't thing of right now. Evaluate your ride and work out an average calorie burn for hour and go with that. Skip the exact numbers unless you want to do a random check or need a baseline to change up your training.

[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.

[DarcyInOregon]

Linda, if you don't solve the problem, you can ask your question at the Garmin Forums: https://forums.garmin.com/

When I was new to using the Garmin some years ago, I got low heart rate readings over a ride when I didn't check my heart rate before starting out to make sure the chest strap was transmitting correctly. I learned to always check the heart rate before putting the Garmin on my bike, and that solved the problem. Sometimes the chest strap was too loose. Othertimes, the bra band bumped out the chest strap, which interfered with transmission. When you are checking your heart rate after turning on the Garmin, the heart rate should be about the same as if you are at home washing dishes, i.e. standing up and doing a bit of body movement, not sitting or sleeping. If fussing with the strap and clothing isn't effective, then put a new battery in the chest strap, and if that doesn't work, then try asking in the Garmin Forums.

Once you get the Garmin to working for you, you will love it. Just about every cyclist in the two training groups in which I participate have a Garmin and there are zero complaints as to accuracy.

[bellissima]

nscrbug, The new Garmin uses Prediction of functional aerobic capacity without exercise testing as one of the parameters to calculate your calories, make sure that your "Activity Class" is set up correctly on your device profile, also the gender, age, weight and height values have to be correct as this would cause a low or high calorie values depending on the activity class setting. You may have to change the Activity Class settings in order to get more accurate calorie count reading.

[nscrbug]

Darcy...I've been perusing the Garmin forums for the past 2 days. I've found several threads discussing the "low calorie burn" issue, but haven't really come across a solution for it. So...my plan of action is to test the unit against my own pulse rate before I ride, and then change the battery in the HR strap to see if that helps. I've only had it for a little over a month, so I'm guessing it's not a low battery issue...but for $5, I'll give it a shot. I'm also going to buy a bottle of HR gel to use on the contacts. I'm fairly certain that my bra is not the cause, because I position the HR strap underneath the bottom band of my bra and it generally doesn't budge at all. IF, after all these attempts, I'm still not getting any love...then I will contact Garmin about getting a replacement strap...maybe I got a bum one.

[nscrbug]

nscrbug, The new Garmin uses Prediction of functional aerobic capacity without exercise testing as one of the parameters to calculate your calories, make sure that your "Activity Class" is set up correctly on your device profile, also the gender, age, weight and height values have to be correct as this would cause a low or high calorie values depending on the activity class setting. You may have to change the Activity Class settings in order to get more accurate calorie count reading.

Hmmm...okay, since I don't actually have my Garmin right in front of me...can anyone tell me what the different "activity classes" are? And how would one determine which class is the correct one? I'm sure I entered a value in for this field, but at the moment I can't remember what it was. Can anyone help?

Linda

[Blueberry]

Hmmm...okay, since I don't actually have my Garmin right in front of me...can anyone tell me what the different "activity classes" are? And how would one determine which class is the correct one? I'm sure I entered a value in for this field, but at the moment I can't remember what it was. Can anyone help?

Linda

You can find the chart here (that's the Quick Start for the 310XT, but I don't think the classes differ. It's a number (1-10) that gives the device an idea of how much you exercise and with what frequency.

[nscrbug]

You can find the chart here (that's the Quick Start for the 310XT, but I don't think the classes differ. It's a number (1-10) that gives the device an idea of how much you exercise and with what frequency.

Thank you!!! I just updated this info in my settings on Garmin Connect...although I am certain that I entered this info on the actual Edge 500 unit itself. I chose to enter a "9" for activity class, even though I'm actually more like a "10", which is over 15 hours/week. I'm at the gym a minimum of 3 hours, 5 days/week...in addition to my long weekend rides which can typically be anywhere between 3-5 hours. Yes...I exercise a LOT. We'll see what happens on my ride tomorrow, with my HR & calorie burn. I'll post an update.

Linda

[bellissima]

Thank you!!! I just updated this info in my settings on Garmin Connect...although I am certain that I entered this info on the actual Edge 500 unit itself. I chose to enter a "9" for activity class, even though I'm actually more like a "10", which is over 15 hours/week. I'm at the gym a minimum of 3 hours, 5 days/week...in addition to my long weekend rides which can typically be anywhere between 3-5 hours. Yes...I exercise a LOT. We'll see what happens on my ride tomorrow, with my HR & calorie burn. I'll post an update.

Linda

Linda, Prediction of functional aerobic capacity without exercise testing is used by Garmin in order to set the values for people that hasn't have a fitness test done or don't know their HR zones, it does not warranty that will set your zones correctly. I believe for you would be a good idea to check what values are set up as your max HR, resting HR and zones as these get set up by the Garmin when selecting you Activity Class at the beginning of the set up. If you know what is your maximum heart rate, resting heart rate and what are your heart rate zones, input those in your Garmin and you'll get a more accurate reading.

[OakLeaf]

bellissima, what do the zones actually mean?

It seems to me, as I said before, that my old old Garmin derived mine reasonably accurately, at least as they correspond to my perceived exertion.

My MHR for running is around 188, resting around 50, but it goes up pretty quickly with any activity. Zone 1 starts at 86 according to the Garmin, which is about where it goes at moderately brisk walking. But then Zone 2 doesn't start until 146, which is about where my respiration rate starts to increase appreciably. I can't run at all, not even a slow jog, with a HR below around 135, and if I can keep it there, I do NOT feel like I'm working.

So from there, zones 2 through 5 are quite narrow - 9 or 10 bpm. That doesn't make a lot of sense, and it's tough when I'm supposed to stay in zone 3, for instance ... but again, it works with my perceived exertion.

What's your take???

[bellissima]

bellissima, what do the zones actually mean?

It seems to me, as I said before, that my old old Garmin derived mine reasonably accurately, at least as they correspond to my perceived exertion.

My MHR for running is around 188, resting around 50, but it goes up pretty quickly with any activity. Zone 1 starts at 86 according to the Garmin, which is about where it goes at moderately brisk walking. But then Zone 2 doesn't start until 146, which is about where my respiration rate starts to increase appreciably. I can't run at all, not even a slow jog, with a HR below around 135, and if I can keep it there, I do NOT feel like I'm working.

So from there, zones 2 through 5 are quite narrow - 9 or 10 bpm. That doesn't make a lot of sense, and it's tough when I'm supposed to stay in zone 3, for instance ... but again, it works with my perceived exertion.

What's your take???

For me zones 1 and 2 are very similar, zone 2 is quite easy and it really doesn’t feel like much work is being done, in the same hand is hard to stay at this zone and it takes some practice as any increase on effort will take me to zone 3, so I would need to pay attention to my computer if I want to stay at zone 2, zone 3 is where I start to feel as I am working and find that if I don’t pay attention I tend to gravitate towards this zone, zone 4 feels hard, it takes concentration to maintain for long periods of time. You zones seem to be somewhat off, If we calculate your zones by just using your MAX HR being 188 and using percentages your zones may look similar to: Zone 1 (Active Recovery) 94-112, Zone 2 (Endurance) 113-131, Zone 3 (Tempo) 132-149, Zone 4 (Threshold) 150-168, Zone 5 169-188. At 146 bpm you would be at the upper part of zone 3. The best way to calculate your zones is by doing a test and calculating your actual threshold.