Which calories burned count is more accurate?

qwerty20142016
qwerty20142016 Posts: 3
in Fitness and Exercise
Hi. I ride my bike for exercise. Yesterday I went on a 20 mile bike ride which took me 1:25:00 which means an average speed of about 14.3 miles per hour. I want to get a fairly accurate grasp of how many calories I burned. I use the app ibiker when I ride which says I burned 1,800. My fitness pal says 1,270. And the app Runkeeper would've told me about 800 which I used to use before I found ibiker. Which app is more accurate in your opinion? I should also add that the terrain I ride on is flat with no major rise or fall in elevation. Thanks

Replies

  • ChrisManch
    ChrisManch Posts: 46 Member
    They are all only guesstimates. Something connected to a heart rate monitor would give more accurate results, but the only way to get fully accurate results would be to measure your oxygen intake and CO2 production, which can only be done in laboratory conditions.

    Don't get hung up on numbers.
  • Velum_cado
    Velum_cado Posts: 1,608 Member
    I can't really say, but no app is going to be particularly accurate. A hear rate monitor will give you a better idea because it can tell just how hard your body worked. It will still be only an estimate, but if you're using an app, you may as well just guess.
  • Shropshire1959
    Shropshire1959 Posts: 982 Member
    They are ALL estimates and there are WAY TOO MANY variables.... Like ->.

    What do your weigh?
    How fit are you?
    How heavy is your bike?
    How much wind was there?
    How Hot/Humid was it?
    What surface were you riding on?
    Were your tyres at the correct pressure?
    What was the gradient profile of your route?
    etc...
    etc...
    etc..

    Want to be 'more' accurate? .. Use a HRM

    Want to be 'more' accurate again? .. Use a Power Meter
  • Zoe_lifts
    Zoe_lifts Posts: 120 Member
    Before I got a heart rate monitor i also used to check it with 2 different apps and myfitnesspal. I always entered the lowest number i could find. So i would go with the 800 calories burned :)
  • Donners185
    Donners185 Posts: 329 Member
    All of the above. Not completely accurate methods for measuring calories burned but to answer your question I'm guessing about 800. Although we are completely different people I burn roughly 600 cals per 60 min spin class with an average HR of 160, max HR 185 (roughly). Again it depends on a number of things. You should get a HRM if you are looking to keep a better record of calories burned. They may not be as accurate as a VO2 Max test but it should give you a general idea.
  • lucasmoten
    lucasmoten Posts: 143 Member
    When I actually care about calories burned and make adjustments, I keep things very very simple... At least, in my head this makes sense because I know how this number is derived and can make adjustments to any individual portion.

    Take body weight and divide by 10. Multiply by number of minutes. Multiply by exertion intensity as a percentage of max. Subtract calories that would have been burned by sedentary rest

    Example...
    180 pounds, yields 18 calories per minute potential. For 1 hour, that's 1080 calories. Running at about 80% max exertion results in 864 calories. Then subtracting do nothing calories (for an hour at that weight, its close to 84), and I'd end up with 780 net calories.

    With that above example, I would have typically ran about 6 to 6.5 miles in the span of an hour. So roughly, at 180 pounds, I'd burn a net 120-130 calories per mile, or 13 net calories per minute when I'm running.

    Here's an example for someone 140 pounds, that may not run with as much intensity... more of a casual easy run...
    140 pounds, 14 calories per minute potential. Over an hour, that's 840 calories. At 70% max exertion, that's 588 calories. Subtract sedentary calories (~70?) and net is now 518. This person may end up running 5 to 5.5 miles, or 94 to 103 calories per mile, about 9 net calories per minute.
    Same 140 pound person, with higher intensity.... we'll say 90% max. A very solid workout..
    140 pounds, 14 calories per minute potential. Over an hour, that's 840 calories. At 90% max exertion, that's 756 calories. Subtract sedentary calories (~70?) and net is now 686. This person may end up running 6 to 6.5 miles, or 105 to 114 calories per mile, about 11.5 net calories per minute.

    In brief, I have my own logical formula(s). They are more accurate then what I've found MFP and machines and even my phone apps and Garmin watches tell me. But this is mainly because my formula trades heart rate for exertion intensity, and favors time over distance for the initial calculations. MFP, at best, overestimates gross calories.
  • Shropshire1959
    Shropshire1959 Posts: 982 Member
    ^ cool
  • _mr_b
    _mr_b Posts: 302 Member
    This is why I got a heart rate monitor!

    They are all estimates but based on my experience those estimates are usually inflated to a degree so I'd say to use the lowest number. For comparison the last big ride I did was 86 miles at an average of 19.7mph and I burned 2570 cals, MFP estimates that would have been 4310!!

    I like Lusas' theory though.
  • qwerty20142016
    qwerty20142016 Posts: 3
    Thanks for all of your feedback. Does anyone know what major store may sell a good heart rate monitor? I know you can get them online but I don't want to wait for 2 weeks
  • Hornsby
    Hornsby Posts: 10,322 Member
    I usually figure around 600 per hour for cycling.
  • lilmiss_sunshine29
    lilmiss_sunshine29 Posts: 136 Member
    I can't really say, but no app is going to be particularly accurate. A hear rate monitor will give you a better idea because it can tell just how hard your body worked. It will still be only an estimate, but if you're using an app, you may as well just guess.

    this
  • qwerty20142016
    qwerty20142016 Posts: 3
    This is why I got a heart rate monitor!

    They are all estimates but based on my experience those estimates are usually inflated to a degree so I'd say to use the lowest number. For comparison the last big ride I did was 86 miles at an average of 19.7mph and I burned 2570 cals, MFP estimates that would have been 4310!!

    I like Lusas' theory though.


    Wow that's really cool! 86 miles?! Where did you ride did you do like laps around your city or did you ride 40 miles to a point then rode back?
  • kickasscleaning
    kickasscleaning Posts: 2 Member
    I just go with whatever count is the lowest. It might feel good that MFP estimates me to have burned 350 calories doing cardio today, but my running app says that it's barely 200. I am inclined to feel that the app is more accurate, and I'd rather accidentally eat 100 less calories than eat over 100 more calories than I intended to.
  • missomgitsica
    missomgitsica Posts: 496 Member
    Your best bet would be to buy a heart rate monitor.
  • Hornsby
    Hornsby Posts: 10,322 Member
    Off Topic, but too the OP (or anyone else that may be interested). Here is the link for the September Cycling Thread where you can log your miles for fun.

    http://www.myfitnesspal.com/topics/show/1419675-september-cycling-challenge-2014
  • hill8570
    hill8570 Posts: 1,466 Member
    Too many unspoken variables. Is this a road bike or something with knobbies? Flat out no stops or having to start / stop a lot? General fitness level? And the list goes on...

    For a flat-out, no-stops ride on a road bike, 800 seems reasonable. On a mountain bike with knobbies, 1270 or more.

    A HRM would be a lot more accurate (for example, I have a hilly single-track course I do once a week or so. Two months back, my HRM gave about 950 calories for the burn. A couple of days ago, it was just a smidge over 800 for the same ride taking the same amount of time. The difference is due to fitness -- two months ago I was maxing my heart rate on a lot of the climbs, now for the same pace I'm 20 bpm off of max, and my heart rate recovers almost instantly once I stop climbing).
  • hill8570
    hill8570 Posts: 1,466 Member
    Thanks for all of your feedback. Does anyone know what major store may sell a good heart rate monitor? I know you can get them online but I don't want to wait for 2 weeks

    What do you have nearby? REI carries a good selection, as do most specialty bike stores. Expect to pay close to list price at either sort of location. Not sure where you get two weeks -- almost anything ordered from, for example, Amazon will show in about three days (OTOH, Bike Nashbar ships slowboat to China).

    For example, the HRM I use: http://www.amazon.com/Zephyr-HxM-BT-Wireless-Sensor/dp/B002PL33AQ (which directly integrates into Endomondo). But there are a number of them out there, depending on what sort of features you're looking for.

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