Accuracy of calories burned while biking

[nscrbug]

So I've been using my Garmin Edge 500 for a few weeks now and really like it. I think it's really cool to upload my rides to Garmin Connect and see all the ride data and graphs. The one thing that has me a bit skeptical is the amount of calories burned. I'm just not sure that I trust it, and I'd like to get opinions from others that are using the 500 to see if their results are similar.

I wear the HR strap (and yes, I do have it on correctly, as I've read that this can make a difference), and I wet the sensor patches on it before putting it on. I've entered my profile information correctly - weight/height/gender, etc. So here are the stats from my last 2 rides -

Ride 1
Time - 04:33:17
Distance - 71.05mi
Elev Gain - 659ft
Ave Temp - 56.5F
Avg Speed - 15.6mph
Avg HR - 108bpm
Max HR - 132bpm
Calories - 771

Ride 2
Time - 04:41:32
Distance - 73.33mi
Elev Gain - 1,745ft
Avg Temp - 76.5F
Avg Speed - 15.6mph
Avg HR - 109bpm
Max HR - 144bpm
Calories - 862

FWIW...I'm roughly 157lbs + bike weight (5'6" & 45 yo). I don't know, but the calorie burn seems awfully low for 4+ hour rides. My average HR is low too, which seems odd especially since I feel like I'm working SO hard (it was windy on both of these rides). I can't seem to ever get my HR very high when riding, as is clearly displayed by my MAX HR on either ride. Yet the effort I put out feels like I'm not just pedaling at a leisurely pace, I'm fighting to keep up with my riding buddy who is quite a bit faster than me...so I don't get it. It's kind of discouraging in a way...to feel exhausted/sore after a long ride, knowing you worked hard...then to see the results of your efforts, only to discover that the numbers are disappointing. I can burn an equal amount of calories at the gym doing cardio and weights in half the time it took me to burn the same amount on a 4 1/2 hour ride. I'm confused by this. :confused:

Linda

[MaTadams]

The calorie burns seem low to me. I've used a Polar HRM in the past and its estimates were definitely higher than my Garmin, but your estimates seem unusually low. Have you tried any of the online calorie burn calculators to compare?

[amb]

I have a polar HRM that is not near as fancy. It's meant more for fitness classes and such, not biking. Here are my stats from today:

Distance: 24 miles
Total time: 1h:42m (incl stops)
Terrain: sort of flat, slight hills
Avg HR: 141
Avg speed: 15 mph +/-
Cal burned: 750

About me: 33yo, 5'-7", 130 lbs.

To me, your calories seem very low for 4+ hrs of riding but what do I know?! I often wonder the accuracy of HRM anyway.

[callmej]

I don't have a garmin, but use a Sigma bike computer. Your numbers, both in terms of calories burned and avg heart rate seem low to me, but maybe my signma is giving me higher numbers than actual. I just returned from a 20 mile ride, monderately hilly (I don't know the elevation gain, but I was huffing and puffing up a couple of the hills) , avg speed 15 mph - my avg heart rate was 144 and calories used 1159. I'm impressed with the length of your rides and your avg speed over those distances:)

[Triskeliongirl]

I think both your HR and cal numbers are low, compared to what I get on a similar ride on a very basic polar HRM. I don't know much about the garmin units, but on the polar you need to be sure to wet the contacts on the strap, so maybe you need to review that you put the HRM on correctly.

[Glory]

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.

[nscrbug]

I think both your HR and cal numbers are low, compared to what I get on a similar ride on a very basic polar HRM. I don't know much about the garmin units, but on the polar you need to be sure to wet the contacts on the strap, so maybe you need to review that you put the HRM on correctly.

Yes, I do make sure to wet the contact points on the strap...and I also make sure that the strap is put on correctly - the GARMIN logo on the HR sensor facing right-side up...which it always does. I'm not sure what else I could possibly be doing wrong to get such low HR and calorie numbers...it's perplexing to say the least.

But I do feel a bit better knowing that you have all confirmed my beliefs of the low numbers. I'd be interested to hear if any other Garmin users are having similar experiences.

Linda

[azfiddle]

I use a Garmin 305. I rode 20.5 miles today, about 1 hour 22 min, and I burned about 800 calories. When rode 73 miles 2 weeks ago, 4 hrs 23 min, it said I used almost 3000 calories. Even if you're in great shape, you must be burning 500 calories an hour or more....

I can ask my DH who is the Garmin wizard around here. Did you set it up for your gender, weight etc?

[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. :p

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...

[Mr. Bloom]

My Garmin is closely in line with normal Calorie burn charts...it registers more with speed and climbing.

I plan on 60-70 calories per mile

[emily_in_nc]

Linda, have you tried taking your pulse manually while wearing the Garmin to see if the numbers are close? For example, stopping at the top of a hill when you feel that your heart is pounding or beating fast and taking your pulse at your wrist or neck while the Garmin is also taking it? You could try this at rest too. It's a simple test but may point out a discrepancy.

When I used to wear a Polar HRM, my max HR was usually around 180 or 190 and average HR around 150+ on a ride, and my calories burned about 400 per hour, and I'm little (<105 lbs). My DH, who weighs in the 150s, always burned a lot more calories than me on the same ride, according to his Polar, even tho his average HR was quite a bit lower than mine.

I agree with others, your numbers seem very low, though the calorie number is low b/c of the HR being low, so that's why I suggested verifying the unit is measuring your HR correctly. If it is, then you are very, very fit!

[nscrbug]

I use a Garmin 305. I rode 20.5 miles today, about 1 hour 22 min, and I burned about 800 calories. When rode 73 miles 2 weeks ago, 4 hrs 23 min, it said I used almost 3000 calories. Even if you're in great shape, you must be burning 500 calories an hour or more....

I can ask my DH who is the Garmin wizard around here. Did you set it up for your gender, weight etc?

Yup, I sure did. It was fairly self-explanatory, so I don't think that I screwed anything up in doing so. That would be great if you could ask your DH...I can use any help I can get in sorting this issue out. Thanks!!

Linda

[OakLeaf]

Comparing your stopwatch pulse is a really good idea.

Do you have the new "premium" soft strap? Those are notorious ...

[nscrbug]

Comparing your stopwatch pulse is a really good idea.

Do you have the new "premium" soft strap? Those are notorious ...

Yes..it is the premium soft strap...which means what exactly? Are these straps known to cause inaccurate readings?

[OakLeaf]

Yes..it is the premium soft strap...which means what exactly? Are these straps known to cause inaccurate readings?

Yep. Known to lose contact if you're too wet, too dry, wearing the wrong kind of fabric ... I've got the old hard strap so I don't really know the ins and outs and whether there's much you can do short of replacing it, but take a look at the Garmin user forums.

[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:confused:

[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 (http://www.tramsoft.ch/downloads/garmin/manuals/garmin_forerunner310xt/forerunner310xt_quick-start-manual_en.pdf) (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 (http://www.tramsoft.ch/downloads/garmin/manuals/garmin_forerunner310xt/forerunner310xt_quick-start-manual_en.pdf) (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.

[MollyJ]

I have a Polar FT 7, which is pretty basic. I came into HRM's and more aggressive bicycling through weight loss. I lost and have kept off for more than a year about 47 pounds.

Here's the news: As you become more conditioned,your calorie burn falls. :( Just ain't fair. But if I understand the physiology correctly, being more physically active kicks up your basal metabolic burn somewhat. You benefit from being more active and less sendentary.

I used the weight loss web site Calorie King and they have estimators for exercise (you can eat back calories burned with exercise). The commonly accepted scuttlebutt was that the estimates were high and the numbers you got with an HRM are "more accurate" and uniformly lower than the estimates. This has tended to be my experience also.

But they are really scientific best guesses, though I think they are not all wrong.

With exercise I have seen my resting heart rate drop. I did an estimation of body fat at my local YMCA (not the gold standard,which is an immersion test).

But with my new bike (did I mention I have new Trek Madone?) my plan is to work on cadence and then I will be interested to see if this kicks up my calorie burn.

Try not to focus on one number. Look at a constellation of data. There is no doubt that the "king" of calorie burn exercise is running. But I like biking. And that beats being a couch potato any day.

[DarcyInOregon]

Classic MapMyRide has a pretty good calculator for determining one's heart rate zones if you know your maximum heart rate, or you can accept the calculator's formula for maximum heart rate.

http://classic.mapmyride.com/calculate_mhr

There is a good explanation of each zone as pertaining to cycling.

The calculator's formula for calculating the maximum heart rate actually works for me. At my age and based on knowing my heart rate at maximum exertion, I estimated my maximum heart rate to be between 165 and 170, and the calculator states 169, so right in the range I thought it was.

[OakLeaf]

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... :cool: 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?

[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... :cool: 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.

[nscrbug]

I just wanted to post an update. So this weekend, I changed the battery in my HR strap (even though I didn't think I needed to), picked up a bottle of HR electrode gel and applied it to the HR strap, and took a manual pulse to see if it was close to what my Garmin was showing right before I set off on my ride. My HR was sitting right around 75-78, just futzing around getting on my gloves and so forth...which was right on target with what my manual pulse reading was. So, I established that the HRM seemed to be working properly at the time. I also double-checked my profile on the Garmin, and made sure that all the data was entered correctly - ht 5'6", wt 157lbs, Female, 44yo, activity class = 9.

After 3 consecutive days of riding, the results of my HR/calorie data were the same as before. On Sat, my avg HR was 101; on Sun, 109; and today, 108. Calorie burn was 888 (65 miles), 1,147 (83 miles), and 551 (43 miles) respectively. I don't know, it just seems weird that I cannot seem to get my HR up at all on the bike. I can safely say that I have NEVER even come anywhere close to hitting my MHR while riding. Is it possible that I just have a freakishly low HR? I normally don't wear a HRM at the gym, but now I am curious to see if it's that low during any kind of activity.

Don't know if this matters or not, but I do remember last year during a routine colonoscopy I was hooked up to a monitor and I kept setting off the alarms on it because my HR kept dipping below 40....freaked out the nurses. Maybe I just naturally have a lower HR? I don't know....

Linda

[DarcyInOregon]

The only other thing I can think of is your cycling position, can it be moving the chest strap away from contacting with your flesh? I can't wear a chest strap on the spin bike at the gym because some of the positions interfere with the chest strap, and maybe it is the same for you on your bike.

Regarding the low heart rate, the people I know with low heart rates during cardio exercise are on heart medications. I also chatted with a female cyclist a few years ago, who had transtioned to the bike from long distance running, and she couldn't get her heart rate anywhere near her max rate on the bike, but I am sure her average rate was over 120. So if you are not on heart meds, maybe you are super fit from another sport and the bike is too easy for you, or perhaps you need to do more miles of steep climbing?

Yesterday I biked an event metric. I looked at the Garmin data of a training group friend who did the metric too. When climbing the nasty hill, his heart rate was around 180; my heart rate was around 140, and that is a huge difference, though my max is only 165-170. But when I looked at the other data, his cadence was 80 and my cadence was 60, his speed up the steep hill was 8 mph and my speed was only 6 mph. He was able to push harder because he is a male or more fit, and got a higher heart rate due to more exertion. On the other hand, at the top of the hill was this one male cyclist who was younger than everyone in my group, and he was off his bike gulping in air like a landed fish, looking like climbing that hill just about killed him.

If your heart rate remains low when climbing real steep grades and you are exerting yourself fully, then my suggestion is see your doctor and make sure you are heart healthy. If your heart is fine, then guess you shouldn't worry about it.

[goldfinch]

Too many possibilities. You can also have depressed heart rates from fatigue and overtraining. (As well as elevated rates--can go either way).

A good time to measure your resting heart rate is while you are still in bed, right after waking up.

[nscrbug]

The only other thing I can think of is your cycling position, can it be moving the chest strap away from contacting with your flesh? I can't wear a chest strap on the spin bike at the gym because some of the positions interfere with the chest strap, and maybe it is the same for you on your bike.

Regarding the low heart rate, the people I know with low heart rates during cardio exercise are on heart medications. I also chatted with a female cyclist a few years ago, who had transtioned to the bike from long distance running, and she couldn't get her heart rate anywhere near her max rate on the bike, but I am sure her average rate was over 120. So if you are not on heart meds, maybe you are super fit from another sport and the bike is too easy for you, or perhaps you need to do more miles of steep climbing?

Yesterday I biked an event metric. I looked at the Garmin data of a training group friend who did the metric too. When climbing the nasty hill, his heart rate was around 180; my heart rate was around 140, and that is a huge difference, though my max is only 165-170. But when I looked at the other data, his cadence was 80 and my cadence was 60, his speed up the steep hill was 8 mph and my speed was only 6 mph. He was able to push harder because he is a male or more fit, and got a higher heart rate due to more exertion. On the other hand, at the top of the hill was this one male cyclist who was younger than everyone in my group, and he was off his bike gulping in air like a landed fish, looking like climbing that hill just about killed him.

If your heart rate remains low when climbing real steep grades and you are exerting yourself fully, then my suggestion is see your doctor and make sure you are heart healthy. If your heart is fine, then guess you shouldn't worry about it.

I did a steep but short climb on my ride this morning. I was monitoring my HR throughout the climb...my HR peaked at 131 (which also happens to be my max HR for this ride), and this is a very challenging hill for me. I have to ride in my absolute lowest gear...my speed up this hill is about 7mph, if that, so cadence is sure to be low as well. As for the possibility of my strap being moved while riding...I think it's unlikely. I generally have to "peel" the thing off me when I'm done, so it pretty much stays put once I put it on.

ETA - not on any heart meds

[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.

[shootingstar]

What do people do after they have lost weight and measured calories during the weight loss process? Do you still do it this carefully?

Hopefully some people reach a point that they know instinctively how much and what to eat works for them in accordance to a rough guessestimate of their exercising activity.

[azfiddle]

For me, it's still a guessing game- I stayed even for a while, gained a few pounds, dropped all but one and stayed there for a couple months, but the next time I seem I went up, I seem to have found an equilibrium that is 3 lbs above my goal. So I'm riding 100 miles a week but can't seem to get these 3 lbs off. It's all about counting and tracking and I think I haven't been as good at that.

Interesting how the Garmin gave a more realistic result w/o the HRM.

nscrbug - did you ever try contacting Garmin to ask them about the discrepancy? My DH did not have any other ideas...

[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

[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]

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]

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.

[Bike Chick]

Linda, based on both our experiences with this, I'm going to do some research on the Garmin site and let you know what I find out.

We did the 15 mile TT course last night with some grueling hills. My time was 50 minutes with a 17.1 average. I did not wear my hrm and the Garmin said I burned 759 calories. Just for comparison I went to caloriesperhour.com and put the info in and it said I should've burned 690 which is pretty close. Had I worn the hrm, it probably would've said 350!

[Bike Chick]

I just googled the term "Garmin 500 not calculating calories" and got a page full of the same complaints. Many forums, including Garmin's, have posts that address this issue so it's not just us. What I did read is that Garmin is aware of the issue and they will be coming out with a firmware upgrade to fix it soon. All I can say is just keep upgrading your Garmin when there is a firmware upgrade and see if it fixes the problem. Everything else on the 500 works great and I'm pleased with the computer in every other aspect.

[tongue_tied]

I mostly don't use the HR strap with my 500 because it gets irritating sometimes. But I've noticed that the 500 overestimates the calories burned, IMO, on a ride without the use of the strap. I was on the North Branch Trail this past Saturday, finished a 60 mile ride, and burned something like 3300 calories in 3 hours. No real climbing. My avg speed was 18mph. Even at 175, I think that's overestimating.

I've just learned that it's a loose gauge of calories burned.

[hulagirl]

coming into this late but my hubby has an extremely low HR.

He's in the 40's sometimes.

Has had ER people totally FREAK OUT on him.

But, he's a marathon runner and in very fine shape.

My HR just getting out of the house is your average HR on the bike! My Max is 180ish. My resting is in the 60-70 range.

When I run with my husband, I get into the 150's while he's MAYBE at 100.

But when we bike, I average lower than he does as I'm a more efficient biker. (on a lighter bike too)

If you know your resting HR, it will tell you a lot about your results. If you are not working hard enough to get that HR up, you won't burn the calories. You are efficient. Your heart is strong. (as long as you have a good recovery HR too!) And the better you are at something, the less you will have to work at it.

You do sound like my husband, very low HR. And that's just what you have to work with. Make sure you enter your resting HR in the garmin as well. That will help change the calculations.