Calculating calories burned while cycling

bobbywarren70
bobbywarren70 Posts: 2 Member
edited November 16 in Fitness and Exercise
what is the best way to accurately calculate calories burned while cycling? I have just started cycling and have been using calories calculated from MFP but I have seen it mentioned that MFP a isn't accurate. I also keep track with map my ride and it is about 30% higher than MFP. What is the best way calculate calories burned?

Replies

  • Mr_Knight
    Mr_Knight Posts: 9,532 Member
    I use bikecalculator.com
  • colejkeene
    colejkeene Posts: 84 Member
    Get a heart right monitor. To be honest it's the best way to calculate calorie burn for all exercises. Each person's burn is different and no computer algorithm is going to be able to reflect your personal body's burn rate.
  • jacksonpt
    jacksonpt Posts: 10,413 Member
    edited April 2015
    There is no accurate.

    7 * # of minutes cycling is going to just as "accurate" as an HRM, MFP, an app, etc.
  • glevinso
    glevinso Posts: 1,895 Member
    jacksonpt wrote: »
    There is no accurate.

    7*# of minutes cycling is going to just as "accurate" as an HRM, MFP, an app, etc.

    That isn't quite true. If you invest in a power meter you can get very close. Even better you can do a metabolic efficiency test, and then couple that information with the data off the power meter to get even closer still.
  • jacksonpt
    jacksonpt Posts: 10,413 Member
    glevinso wrote: »
    jacksonpt wrote: »
    There is no accurate.

    7*# of minutes cycling is going to just as "accurate" as an HRM, MFP, an app, etc.

    That isn't quite true. If you invest in a power meter you can get very close. Even better you can do a metabolic efficiency test, and then couple that information with the data off the power meter to get even closer still.

    Fair enough.

    For the average MFPer, there is no accurate.

    7*# of minutes cycling is going to just as "accurate" as an HRM, MFP, an app, etc.
  • glevinso
    glevinso Posts: 1,895 Member
    Agreed. A heart rate monitor with GPS is probably going to be the best "reasonable" solution, and as long as you are mostly riding steady state (IE you aren't doing short intervals) it will be close enough.
  • jacksonpt
    jacksonpt Posts: 10,413 Member
    edited April 2015
    glevinso wrote: »
    Agreed. A heart rate monitor with GPS is probably going to be the best "reasonable" solution, and as long as you are mostly riding steady state (IE you aren't doing short intervals) it will be close enough.

    You mention an HRM with GPS... do the newer/better calorie burn equations factor in elevation changes (i.e. climbing vs descending)?
  • glevinso
    glevinso Posts: 1,895 Member
    jacksonpt wrote: »
    glevinso wrote: »
    Agreed. A heart rate monitor with GPS is probably going to be the best "reasonable" solution, and as long as you are mostly riding steady state (IE you aren't doing short intervals) it will be close enough.

    You mention an HRM with GPS... do the newer/better calorie burn equations factor in elevation changes (i.e. climbing vs descending)?

    I am not certain but I seem to recall some discussion over the algorithms the newer Garmins use in absence of a power meter. Has something to do with combining speed data with the HRM to get a more accurate picture. I could be thinking of something entirely different though so perhaps I am wrong here.
  • DaveinSK
    DaveinSK Posts: 86 Member
    glevinso wrote: »
    jacksonpt wrote: »
    There is no accurate.

    7*# of minutes cycling is going to just as "accurate" as an HRM, MFP, an app, etc.

    That isn't quite true. If you invest in a power meter you can get very close. Even better you can do a metabolic efficiency test, and then couple that information with the data off the power meter to get even closer still.

    That's interesting. Most power meters are crazy expensive, but I believe I have a bottom bracket torque/cadence sensor in a box with a bunch of other ebike parts that never ended up being used for anything. Do any of the common Garmin-style bike computers accept torque/cadence inputs, or are all the systems pretty closed?
  • glevinso
    glevinso Posts: 1,895 Member
    DaveinSK wrote: »
    glevinso wrote: »
    jacksonpt wrote: »
    There is no accurate.

    7*# of minutes cycling is going to just as "accurate" as an HRM, MFP, an app, etc.

    That isn't quite true. If you invest in a power meter you can get very close. Even better you can do a metabolic efficiency test, and then couple that information with the data off the power meter to get even closer still.

    That's interesting. Most power meters are crazy expensive, but I believe I have a bottom bracket torque/cadence sensor in a box with a bunch of other ebike parts that never ended up being used for anything. Do any of the common Garmin-style bike computers accept torque/cadence inputs, or are all the systems pretty closed?

    Not sure what you mean by a torque sensor. That is all a power meter really is.

    Garmins accept data via ANT+ from all kinds of sensors. I used a crank-spider power meter on my tri bike (a Quarq Riken), and a hub-based Powertap on my road bike. It also gets data via ANT+ from a wheel-speed and crank-arm magnet cadence sensor and the usual ANT+ heart rate monitor.
  • handyandy9x
    handyandy9x Posts: 93 Member
    Most of the better Garmin bike comps should have the ability to read a cadence sensor, as well as a HRM. They use the ANT+ standard. They give a pretty reasonable calorie burn as it takes into account the elevation too.
  • tycho_mx
    tycho_mx Posts: 426 Member
    DaveinSK wrote: »
    glevinso wrote: »
    jacksonpt wrote: »
    There is no accurate.

    7*# of minutes cycling is going to just as "accurate" as an HRM, MFP, an app, etc.

    That isn't quite true. If you invest in a power meter you can get very close. Even better you can do a metabolic efficiency test, and then couple that information with the data off the power meter to get even closer still.

    That's interesting. Most power meters are crazy expensive, but I believe I have a bottom bracket torque/cadence sensor in a box with a bunch of other ebike parts that never ended up being used for anything. Do any of the common Garmin-style bike computers accept torque/cadence inputs, or are all the systems pretty closed?

    Not a straightforward answer - Garmins and other head units don't usually do the math, it's done internally and the ANT transmitter sends the instantaneous power number to the head unit. Heck, even some cellphone apps can get them. I believe the sampling rate is 1 Hz for systems that communicate to a an ANT+ receiver, but other power meters like SRM, Polar, Powertap, etc. have different sampling rates.

    Also - not all the Garmin head units are set up to "receive" power readings. The 500, 800, 1000 certainly do, but some of the multisport watches do not.

    And yeah, the power meter doesn't lie, as long as it is reasonably calibrated. Still not perfectly accurate, but much better than pretty much any system for any sport.

  • glevinso
    glevinso Posts: 1,895 Member
    edited April 2015
    For what it's worth... There are 4.18 joules per calorie (or 4.18kj per kcal). There is also a very happy accident that the human body is approximately 25% efficient at converting energy in the body into power into the pedals. There are only small variations in efficiency for elite cyclists and untrained (Between 24% for untrained and 27% for Tour de France level riders). Therefore there is almost exactly a one-to-one relationship between calories burned and kilojoules expended. The power meter will tell you exactly how many kilojoules it sensed you put into the crank. This just *happens* to correlate within a few % to the number of kcal burned. (IE kj/4.18 * 4 is close enough to the kj, so just go with kj)
  • sijomial
    sijomial Posts: 19,809 Member
    edited April 2015
    I actually find MFP's 14-16mph "guesstimate" compares quite well (for me) to both a power meter and a properly calibrated HRM.

    The 16-20mph category is far too wide a spread to be useful, there's a world of difference between a 16mph and a 20mph ride (again for me, as a not very aerodynamic rider).

    Garmin far too low, Strava a bit too low, Runkeeper too high.

    Accuracy is overrated IMO - a bit of common sense and consistency goes a long way.
  • DaveinSK
    DaveinSK Posts: 86 Member
    edited April 2015
    glevinso wrote: »
    DaveinSK wrote: »
    glevinso wrote: »
    jacksonpt wrote: »
    There is no accurate.

    7*# of minutes cycling is going to just as "accurate" as an HRM, MFP, an app, etc.

    That isn't quite true. If you invest in a power meter you can get very close. Even better you can do a metabolic efficiency test, and then couple that information with the data off the power meter to get even closer still.

    That's interesting. Most power meters are crazy expensive, but I believe I have a bottom bracket torque/cadence sensor in a box with a bunch of other ebike parts that never ended up being used for anything. Do any of the common Garmin-style bike computers accept torque/cadence inputs, or are all the systems pretty closed?

    Not sure what you mean by a torque sensor. That is all a power meter really is.

    Garmins accept data via ANT+ from all kinds of sensors. I used a crank-spider power meter on my tri bike (a Quarq Riken), and a hub-based Powertap on my road bike. It also gets data via ANT+ from a wheel-speed and crank-arm magnet cadence sensor and the usual ANT+ heart rate monitor.

    You need rotational speed and torque to calculate power, torque in Nm * rotational speed in radians/sec = power in Watts. What I have is just a dumb sensor.

    I checked and I did buy a Thun X-Cell RT, so hopefully it's still kicking around somewhere. It just has raw torque and speed outputs though, so it doesn't sound like it would be an easy interface.
    I do have an Ant dev kit in another box though, converting it to a wireless power meter might be a fun project.
  • glevinso
    glevinso Posts: 1,895 Member
    sijomial wrote: »
    The 16-20mph category is far too wide a spread to be useful, there's a world of difference between a 16mph and a 20mph ride (again for me, as a not very aerodynamic rider).

    This is an odd category for MFP to group together. 16mph for me is about 140 watts on my road bike, on a flat road with no wind. 20mph is closer to 180 watts. 140 watts for an hour is 504kj (so figure 500 calories) and 180 watts for an hour is 648kj (lets just round to 650cal). That is a pretty big difference.

This discussion has been closed.