Calorie Counter

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Calories Burned - Stationary Bike

aeloineaeloine Posts: 2,163Member Member Posts: 2,163Member Member
Good afternoon!

I go to spin class and it gives me kcal and kj burned but I don't input my height/gender/weight.

My question is, are those burn numbers absolute or are they weight relative? For reference, I'm roughly 220 lbs and I've been "burning" around 300 kcal/hour which seems a little low.

Don't get me wrong, I'm definitely not putting out very high watts yet (there's been a lot of improvement in my averages over the last couple of months in terms of watts/miles "ridden" per hour) but if 1 mile run/jog is ~100 calories and I can do 4+/hour, and I feel like I'm exerting significantly more weight effort on the bike, shouldn't my burn be higher?

I guess I'm hoping that I'm burning more due to my (relatively) higher mass. Plus, my little HR enabled FitBit is giving me higher calorie burns. FitBit has always overestimated, but rarely triples what any other "calories out" meters estimate.

Thanks in advance!
edited May 2018
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Replies

  • serindipteserindipte Posts: 1,557Member Member Posts: 1,557Member Member
    If you aren't entering your stats, its a generic and inaccurate estimate.
  • 100_PROOF_100_PROOF_ Posts: 1,175Member Member Posts: 1,175Member Member
    Those estimates are inaccurate.
  • NorthCascadesNorthCascades Posts: 9,592Member Member Posts: 9,592Member Member
    If it's measuring watts it has the most accurate calorie measurement possible outside a lab, with a maximum error of 5%. The number is absolute, not scaled to your weight (just like the calories on a food label).
  • cooicooi Posts: 9Member Member Posts: 9Member Member
    Does the machine you use measure kJ? That is the amount of work done in the time you're on it? This will be the actual calories you've burnt during this time.
  • heybalesheybales Posts: 17,300Member Member Posts: 17,300Member Member
    To clarify - it's the amount of energy put into the pedals to turn them.

    Not your BMR level burn that is also occurring, not the energy needed by back/arm/chest muscles to keep holding on and balance.
    During that chunk of time you are actually burning more than that literally.

    If you were to manually log that on Fitbit (and you should), it would be replacing the Fitbit calorie burn for that chunk of time - and that burn should include the BMR level in it.
    Just find out how much your sleeping time burn is for same amount of time - and add that too it to at least get closer to reality.

    But it is more accurate than HR the Fitbit is using for calculations.

    I always had elevated HR because of the heat in a spin class, compared to same effort outside - will, until it was summer and same issue there.

    Oh - when you manually add it as Spin bike, and put in your own calorie burn - you can leave the Fitbit Activity Record alone - that contains the HR info that will still be useful for review later to compare.
    There is no double logging, Fitbit is a replace only system, not add to system. Besides the Activity Record will give you the start and duration to use when creating your Workout Record.
  • scorpio516scorpio516 Posts: 941Member Member Posts: 941Member Member
    If it's measuring watts it has the most accurate calorie measurement possible outside a lab, with a maximum error of 5%. The number is absolute, not scaled to your weight (just like the calories on a food label).

    And if the power meter on the bike is accurate.

    On gym equipment, I don't know what's involved with maintaining and zeroing the PM, or if it even is a direct force.

    Tl:Dr what the bike says it's probably right, but might not be in rare occasions
  • serindipteserindipte Posts: 1,557Member Member Posts: 1,557Member Member
    sijomial wrote: »
    Your weight isn't really that significant for a non-weight bearing exercise.
    Pedal standing up and that changes of course....

    For cycling converting watts (power) to calories is by far the most accurate way to estimate net calories burned.
    Reverse calculating your 300 cal / hour rate of burn would be an average of 83 watts.
    This is how to convert your power to calories:
    energy (kcal) = avg power (Watts) X duration (hours) X 3.6

    The good thing is that your fitness improves your rate of burn will increase.

    @serindipte & @100_PROOF_
    Although many HR based cardio estimates on machines are badly inaccurate converting power to calories is a mathematical formula. The only part that is an estimate is the efficiency ratio but that doesn't vary hugely between cyclists.

    Learn something new every day! Thanks for the info :smiley:
  • jjpptt2jjpptt2 Posts: 4,877Member Member Posts: 4,877Member Member
    sijomial wrote: »
    Your weight isn't really that significant for a non-weight bearing exercise.
    Pedal standing up and that changes of course....

    For cycling converting watts (power) to calories is by far the most accurate way to estimate net calories burned.
    Reverse calculating your 300 cal / hour rate of burn would be an average of 83 watts.
    This is how to convert your power to calories:
    energy (kcal) = avg power (Watts) X duration (hours) X 3.6

    The good thing is that your fitness improves your rate of burn will increase.

    @serindipte & @100_PROOF_
    Although many HR based cardio estimates on machines are badly inaccurate converting power to calories is a mathematical formula. The only part that is an estimate is the efficiency ratio but that doesn't vary hugely between cyclists.

    This.

    Stationary bikes are often fairly reliable. If they measure watts or kj or power, then it's probably as accurate an estimate as you're going to get.

    Also, weight, gender, etc has virtually no impact on calorie burns from cycling.
  • Francl27Francl27 Posts: 26,391Member Member Posts: 26,391Member Member
    My burn on stationary bike was always so low that I honestly stopped bothering. It was really hard on my legs too... I burn more taking a walk!
  • Machka9Machka9 Posts: 16,032Member Member Posts: 16,032Member Member
    On the road, I go with 100 calories for every 5 km. At 20 km/h (my pace), that's 400 calories per hour.

    Because riding an indoor bicycle is easier than riding outside, I go with about 300-350 cal/hour. For 350, I have to be really working hard.

    I don't include anything about my weight, gender, age, etc. in those estimates.
    edited May 2018
  • tbright1965tbright1965 Posts: 843Member, Premium Member Posts: 843Member, Premium Member
    As others have indicated, the bike is likely indicating the energy you are putting into the bike. But you are expending other energy besides turning the pedals.

    My total burn for a 60 minute spin class can be 700-1000 calories, and I burn a bit more on my road bike each hour when I'm keeping a 15-20MPH pace. (often 1000+/hr) I can knock out 36 miles in about two hours and MapMyRide is pretty consistent with my Fitbit Surge (with HR and GPS tracking) and was pretty consistent with my previous MyZone device that measured my heart rate and calculated calorie burn based on my age, gender and weight. They are all within about 10% of each other and my weight loss seems to put them in the ball park.

    I don't know how hard you work on the bike. I weigh a bit more than your stated weight, and I can maintain 300 watts power output for several minutes, and even exceed 500w for 30-60 seconds, but then I'm done.
  • BrianSharpeBrianSharpe Posts: 8,905Member Member Posts: 8,905Member Member
    If it's measuring watts it has the most accurate calorie measurement possible outside a lab, with a maximum error of 5%. The number is absolute, not scaled to your weight (just like the calories on a food label).

    This.....cycling is far less dependent on weight than a load bearing exercise like running unless you're climbing a lot of hills. I had a power meter installed on my own road bike and was extremely disappointed when it came to light that I was burning about 17 cal per km when commuting to work.....roughly half of what my Garmin gave me previously but it's hard to argue with watts.
  • BrianSharpeBrianSharpe Posts: 8,905Member Member Posts: 8,905Member Member
    Francl27 wrote: »
    My burn on stationary bike was always so low that I honestly stopped bothering. It was really hard on my legs too... I burn more taking a walk!

    If you're exercising purely for the calorie burn you're missing the point. I'll bet you were getting your heart-rate a lot higher on the bike than you do walking.
  • aeloineaeloine Posts: 2,163Member Member Posts: 2,163Member Member
    Huge thanks to everyone who answered! I was afraid that the bike was the more accurate measure but *hoping* that it wasn't. I didn't think about it being a non-weight bearing exercise, so that provided quite a bit of insight.
  • tbright1965tbright1965 Posts: 843Member, Premium Member Posts: 843Member, Premium Member
    As others have indicated, the bike is likely indicating the energy you are putting into the bike. But you are expending other energy besides turning the pedals.

    My total burn for a 60 minute spin class can be 700-1000 calories, and I burn a bit more on my road bike each hour when I'm keeping a 15-20MPH pace. (often 1000+/hr) I can knock out 36 miles in about two hours and MapMyRide is pretty consistent with my Fitbit Surge (with HR and GPS tracking) and was pretty consistent with my previous MyZone device that measured my heart rate and calculated calorie burn based on my age, gender and weight. They are all within about 10% of each other and my weight loss seems to put them in the ball park.

    I don't know how hard you work on the bike. I weigh a bit more than your stated weight, and I can maintain 300 watts power output for several minutes, and even exceed 500w for 30-60 seconds, but then I'm done.

    Took a snapshot of my Fitbit estimate of my Les Mills Sprint Class (HIIT) class. The class is 30 minutes. I got there a few minutes early to warm up as I'm coming back from a knee injury, so I need 10 minutes or so to warm up before we start running.

    og07wt3qwocy.png

    So about 1/2 of that session was all out training and the other half was the warmup and cool down.
  • sijomialsijomial Posts: 16,111Member Member Posts: 16,111Member Member
    As others have indicated, the bike is likely indicating the energy you are putting into the bike. But you are expending other energy besides turning the pedals.

    My total burn for a 60 minute spin class can be 700-1000 calories, and I burn a bit more on my road bike each hour when I'm keeping a 15-20MPH pace. (often 1000+/hr) I can knock out 36 miles in about two hours and MapMyRide is pretty consistent with my Fitbit Surge (with HR and GPS tracking) and was pretty consistent with my previous MyZone device that measured my heart rate and calculated calorie burn based on my age, gender and weight. They are all within about 10% of each other and my weight loss seems to put them in the ball park.

    I don't know how hard you work on the bike. I weigh a bit more than your stated weight, and I can maintain 300 watts power output for several minutes, and even exceed 500w for 30-60 seconds, but then I'm done.

    Took a snapshot of my Fitbit estimate of my Les Mills Sprint Class (HIIT) class. The class is 30 minutes. I got there a few minutes early to warm up as I'm coming back from a knee injury, so I need 10 minutes or so to warm up before we start running.

    So about 1/2 of that session was all out training and the other half was the warmup and cool down.

    If you could maintain 300 watts for the entire hour you would be burning net 1080 calories.
    HR is a poor way to estimate calories for interval training - it badly exaggerates your calorie burn while your HR is still elevated during the recovery periods.
    And that assumes you have an average exercise HR anyway - there's a huge variation. I've seen three fit, experienced cyclists pushing out the same power at 120, 150 and 180 bpm.
    edited May 2018
  • AnnPT77AnnPT77 Posts: 14,170Member Member Posts: 14,170Member Member
    Minority report: I think some spin bikes are very inaccurate, and I don't know anything about yours. The ones I use in a class usually say I burn around 600 calories in 45 minutes. That's ridiculous. I burn nothing even remotely like that, even though I'm pushing myself, keeping my heart rate up (per HRM), sweating, and all that good stuff. 250-300 would be much more realistic for me, based on RPE and experience from better-metered exercise.

    In theory, a spin bike could produce a power meter estimate that would be quite useful in estimating calories. Do we know whether your specific bike does that? I'll bet we don't. Mine sure as <bleep> doesn't. ;)
  • scorpio516scorpio516 Posts: 941Member Member Posts: 941Member Member
    sijomial wrote: »
    As others have indicated, the bike is likely indicating the energy you are putting into the bike. But you are expending other energy besides turning the pedals.

    My total burn for a 60 minute spin class can be 700-1000 calories, and I burn a bit more on my road bike each hour when I'm keeping a 15-20MPH pace. (often 1000+/hr) I can knock out 36 miles in about two hours and MapMyRide is pretty consistent with my Fitbit Surge (with HR and GPS tracking) and was pretty consistent with my previous MyZone device that measured my heart rate and calculated calorie burn based on my age, gender and weight. They are all within about 10% of each other and my weight loss seems to put them in the ball park.

    I don't know how hard you work on the bike. I weigh a bit more than your stated weight, and I can maintain 300 watts power output for several minutes, and even exceed 500w for 30-60 seconds, but then I'm done.

    Took a snapshot of my Fitbit estimate of my Les Mills Sprint Class (HIIT) class. The class is 30 minutes. I got there a few minutes early to warm up as I'm coming back from a knee injury, so I need 10 minutes or so to warm up before we start running.

    So about 1/2 of that session was all out training and the other half was the warmup and cool down.

    If you could maintain 300 watts for the entire hour you would be burning net 1080 calories.

    And if you are pushing 300 W for an hour, look into racing
  • heybalesheybales Posts: 17,300Member Member Posts: 17,300Member Member
    AnnPT77 wrote: »
    Minority report: I think some spin bikes are very inaccurate, and I don't know anything about yours. The ones I use in a class usually say I burn around 600 calories in 45 minutes. That's ridiculous. I burn nothing even remotely like that, even though I'm pushing myself, keeping my heart rate up (per HRM), sweating, and all that good stuff. 250-300 would be much more realistic for me, based on RPE and experience from better-metered exercise.

    In theory, a spin bike could produce a power meter estimate that would be quite useful in estimating calories. Do we know whether your specific bike does that? I'll bet we don't. Mine sure as <bleep> doesn't. ;)

    Very true - our spin bikes didn't use watts on the ones upgraded with a little computer add-on.
    It got distance from cadence and known wheel size, and with no other stats (no resistance could be known from felt braking pads) - it gave a calorie burn. I never used one to see if it seemed to be using formula for outside distance with wind resistance, or inside. But no user weight.

    The 2 exercise bikes in other back room were more accurate than that giving watts, but that was your traditional wide seated springy version, and half-recumbent. But at least some manufacturer brochure available to look up info.
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