Strava over-estimates Calories

Does anyone else notice that the calorie info on Strava is a huge overestimate from the amount of calories you actually burn?  Sometimes the estimated calories burned on Strava after I upload my ride is 2 to even over 3 times what I actually burned.  What algorithm is used and why is there such a discrepancy?  

Today alone I did a ride where I only burned 1,500 kcal according to my Garmin computer (which is actually really about 800 additional calories burned over my basal rate.)  Strava states I burned 3,100 kcal.  My Garmin 810 with all of my personal info, HR data, VO2 Max, FTP, etc I know is much more accurate.  

How could Strava possibly calculate anyone who rides for only 45 miles stayed in Z2 70% of the time, Z3 15%, and Z4 for only 1% could possibly burn over 3,000 calories?  I know it is not accurate, but there are people who do depend on this as their only means of calculating calories burned.  Without a HR monitor it exaggerates even more.  It would have indicated that I burned well over 4,000 calories, when I actually burned less than 1,000. 

BTW, when the ride is uploaded on GarminConnect, the calories info is the same as that on my bike computer.

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  • Official comment

    Hi Folks, 

    Earlier last month, we updated our calorie calculations to use the number of calories burned recorded in .FIT and .TCX files instead of our default calorie calculation. If your device records in either of those files, then you'll see those numbers on your Strava activity. 

    You can read the announcement here

  • To Strava Support:

    Why are you not addressing this issue?

    1. It is clear multiple people have the same issue

    2. You have clear data points and support

    3. 30-40% over optimistic calorie recording seems about the norm feedback.

    We need an answer.

    For those of us accurately measuring our calorie intake, your calorie usage inputs are totally undermining the process. 

  • I just posted this to support:

     

    This is a follow-up to your previous request #536488 "Re: Turn ridiculous calorie count off, or disconnect from HealthKit"

    Previously you had posted this formula for how you calculate calories:

    Average speed * 3.6 * weight * 3.413E-4 * moving time
    Where:
    Average speed = grade adjusted speed based in meters/second
    Moving time = in seconds and based on grade adjusted speed
    Weight = athlete weight in kg

    This breaks down to grade adjusted distance in meters * weight in kilograms * 0.00123 or
    Distance in km * weight in kg * 1.23 - 1.23 Calories per kg per km.

    The literature does not support this value.  The generally accepted figure is 0.97 Calories per kg per km.  Please correct this so that I can actually import your values into the calorie tracking app that I use.

    Sources:

    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1859586/pdf/brjsmed00270-0005.pdf

    http://www.runnersworld.com/weight-loss/how-many-calories-are-you-really-burning

    http://www.runnersworld.com/peak-performance/running-v-walking-how-many-calories-will-you-burn (an update)

    http://www.runnersworld.com/sweat-science/mythbusting-running-a-mile-always-burns-the-same-calories (getting into the weeds)

    and also from the Compendium of Physical Activities:

    https://sites.google.com/site/compendiumofphysicalactivities/Activity-Categories/running - work through the math and it agrees closely with the above articles.

  • I have been using Strava to track calories burnt and using myfitnesspal to track my calorie intake. Not being very up on the in and outs of how the calculations are undertaken I have been trusting Strava to provide me with the right information. 

    I have been religiously in my weight of food so I know my calorie intake in correct, however I am still failing to loss weight, the only conclusion I can come too is that Strava is incorrect. 

    I have been using runkeeper app along side Strava and like many people say the calories are much more inline with what the research I have undertaken would seem to suggesting I would be burning. 

    I am extremely disappointed with Strava as someone who is not a fitness professional and is using the app to get fit and loss weight I have found this at times a difficult process to understand what has been going so wrong. I have now canceled my Strava membership and will be moving to using another app. 

     

     

  • If you have a power meter, Strava will estimate your calorie burn as1.15 Calories -  4.7kj roughly - for every 1kj expended.  This assumes 21.5% human efficiency, whereas Garmin will assume about 23% human efficiency.  I find the Strava power based numbers work for me.

    Running is different.  Strava's running calories are consistently 30% high compared to numbers derived from studies where oxygen consumption was measured.  General rule of thumb:  70 Calories per 100 lbs body weight per mile.

    I complained about it on this forum.  One of their employees posted their algorithm.  I couldn't find it anywhere in the literature.  I have no idea where they get it from but it's pretty damned wrong.

    If Strava fixed their running calories I could hook it up to LoseIt and import it straight in.  Unfortunately I have to manually enter my rides from Strava and use LoseIt's far superior running calorie calculations for my runs.

  • I've noticed a big difference in calories expended between my Garmin connected to a chest-strap Heart Rate Monitor and the Strava recording on my iPhone.  Did a little research and realized that the difference was the HRM. Just got a new Apple Watch, which I connected to Strava, and figured that the problem would be solved now that both devices have heart rate info.  Surprise!  Strava doesn't use heart rate info to calculate calories even if available!  Very disappointed.

     

    Why does it matter?  I have type 1 diabetes and have been trying to synch my daily exercise with my food intake on My Fitness Pal.  May switch back to Endomonda because of this.

  • One quick hack Kirsten - set your weight to 0.78 * your actual weight.  Now your calorie burn will be in the ballpark.

    @elle someone looked at my support post but no action has been taken.  I guess Strava is OK with being way off on its calorie calculations.

    I honestly don't know why all these companies have all these different numbers.  Calories burned running, walking and cycling is well established.  There are numerous studies using oxygen consumption that have resulted in well accepted formulas in exercise physiology.  Not using these formulae is just plain incompetence.

  • Another runner here - Strava is over estimating my calorie burn by around 30% when compared to a variety of online calculators and also the Moves app. Definitely an outlier. 

    Is it possible to hack the app by giving myself a weight that would compensate for this error?

  • Strava overestimates running calories too, especially when there is some elevation gain. As I understand the algorithm doesn't use HR data and relies mostly on grade adjusted pace and a few other metrics like athlete weight, time, etc. Strava's algorithm doesn't take athlete's efficiency into account.

  • Strava way overestimates running calories for me by 20%+. For example, today I ran 3.4 miles on a fairly flat path in 31:10 (9:05 / mile pace) and it calculated 588 calories! These seem to be "vanity calories", sort of like vanity sizes in clothes. Every other online running calorie calculator shows in the 414 - 481 range. When will this be fixed?

    (Yes I have correctly entered my weight on my profile.)

  • I just did a 20km ride.  Runtastic cycling estimated ~ 330 cal burned, strava estimated ... ~ 817!  The heart rate monitoring looks accurate, the time, distance, elevation gain all accurate.  Calories ... different story.

    I love the stats on Strava, but not if there are going to be totally off. I will switch apps for now because the calorie count is very useful feature when training.  Also, I am paying premium, but will have to cancel and pay for Runtastic instead unless everything works.

    Fix please!

  • +1 for getting somebody to look at the calories burned during cycling. I'm trying to lose weight using myfitness + strava and currently its letting me eat around 3000-3500 calories a day if I do any kind of  hard cycling... needless to say I'm not losing too much weight...

  • Not to sound like a broken record, but I also have noticed Strava way overestimating running calories burned. I still think it's crazy that they ignore HR data.

  • Hi Jason and Simon,

    I've gone ahead and created a support ticket for both of you.  It definitely shouldn't be showing that many calories, so I'm having our support team look into it for you.  Thanks for letting us know.

    -Shelby

  • Today I decided to test out the accuracy of Stava's calorie calculations.  I intentionally went for a moderate paced short distance ride with very little climbing.  

    Under 30 miles (short ride for me)
    Averaged about 18 mph (very moderate pace for me)
    2,400 ft of climbing (not very much climbing at all)
    All grades were under 10%
    Heart rate never got above zone 4 (it was only in zone 4 for 7% of the time), Heart rate was in zone 1 and 2 for over 60% of the time
    Only out for 1.5 hours.  

    Given this information there is not possible way I burned over 1,000 kcals. According to my computer, I burned a little over 700 kcal.  This is probably pretty accurate considering the little effort I put in, the little time I was out, the the ease of the ride.  

    According to Strava I burned almost twice that, over 1,300 kcal.  I can say for certain that the formula Strava uses to calculate calories is not very accurate at all.  This is a way overestimate.  And I can also tell you that the times I forgot my HR monitor or my HR monitor died, it would have doubled or tripled the value it calculates with my HR monitor.  

    Strava really needs to consider using a different formula for calculating calories.  There are people who depend on accurate information as they are trying to lose weight.  

  • Thanks for the comments about Run calories John - I'll make sure someone takes a look at your post. 

  • I also notice that Strava seems to inflate calorie burn rate by about 15-30% compared to most online calculators. Strava's numbers are definitely an outlier.

  • "I have found that Strava does not calculate enough. 40 mins of cycling w/o HRM)  @ 15.4mph and only burn 315?  Or the others just way over calculate.... Map My Ride said 968."

    Both are way overestimates.  You did not burn 315 calories in only 40 minutes, especially only going 15 mph.  Even if you are in poor shape and 15 mph is hard for you, that is still way to many calories.  Most likely only burned about 1/3 to 1/2 of that.  Map My Ride is ridiculously overdone.  


  • Mapmyride calculates kj, you would need to convert it to kcal and then it gives a reasonable figure.

    It is so annoying that Strava is overestimating calories burned. I went for walk today and it says I burned 380 kcal in 1 hour. There's no way I burned that much, I am 59kg 159m and I'd have to sweat quite a bit to get 380 off.

    Common Strava get this fixed! This is no rocket science, there's so many resources out there to work out an appropriate formula!

  • Are you using a power meter? 

    If so, how many kilojoules did it report?

    If not, was this a road ride or a MTB ride?  Without a power meter Strava will drastically under report calories for an off road ride.

    Take the number of calories reported by Garmin connect.  Divide by hours ridden to get Calories per hour.  Divide that number by 4.  That will be really close to your average watts.  Can you average those watts for the entire duration of the ride?  Consider that top level UCI pros will make 350 to 450 watts over a half hour "finishing climb" and can average 250 watts over 5 hours.  An average Cat 4 can make 4 watts / kg on a half hour climb and maybe 2.5 watts / kg over 5 hours.

  • I use strava to track the way to my office and back. To prevent that I "spam" strava with 2 boring rides a day, i press on pause when arriving at the office and restart when i ride home.

    It looks like stava or whatever crashed in the middle of the pause and strava began to record while sitting in the office, because now I have a (I try tro translate to english) "time in movement" of 2:44 hours instead of ~30 minutes:

    https://www.strava.com/activities/882808010

    And I burned ~2.300 kcal!  Man, that was nice! I immediately drank 10 beers at home to compensate that ;-)

    Perhaps this helps to find out why strava has such a huge gap between reality and calculated calories because it's really a extreme example.

     

  • Just went for a 1-hour walk. Garmin says 564 calories (reasonable given my weight), but Strava says 837 (∆37%), which cannot be right -- no way I was exerting that much. When I checked on a 3rd-party site using weight, distance and pace, estimated calories burned was 607.

    Cycling, however, seems right on. On a 50k ride last weekend, Strava was 2255 Cal and Garmin was 2137 (∆5%). On a 26k ride before that, Strava 1244 vs Garmin 1398 (∆12%).

  • Yep, agree. Sucks that Strava is way overstated on calorie counts. I dropped 12 pounds for my first half marathon this May 7th by using Polar Flow calorie counts synced to Myfitnesspal. 30% off is the difference between achieving your weight loss goals and failing completely.

    Strava, your fitness and freshness, social component, pace, and heart rate analysis is my favourite out of polar, mapmyrun, nike+ run club, and runtastic. You showed me, based on a recent 5K race result, what my lactate threshold pace was so I set a higher goal for my first half marathon than I would have based on my Polar Running Index chart. I beat the Polar prediction by 5 minutes with a 1:38:14 finish versus 1:43:30.

    Why keep this distorted calorie counter in place when obesity is the number one health issue in the USA and Canada?

    Your training programs from Macmillan fitness also are so disconnected from the Strava app. No feedback or proper integration to the app. They're not dynamic based on training missed or benchmarks completed. Mapmyrun, and Nike+ plus Run Club are examples to aspire to. The Polar training program is good also but is purely based on heart rate and time. It doesn't adapt as you go or as you achieve or miss training but have worked for me since I stuck to the plan 100%.

    Overall, I think Strava is great. Fix these gaps and become the Facebook of running apps! Cheers, Blair.

  • Another runner chiming in to say (again) that Strava is massively overstating calories burnt. Please fix this or at least provide users the ability to manually adjust. This is a massive pain when it comes to MFP / LoseIt integration.

  • I thought I should keep this train rolling. I am new to Strava and have found that it grossly overestimated my calories compared to both a wrist HRM and chest HRM. I even connected it to a HRM via Bluetooth but that didn't seem to make any difference. There is a lot I like about Strava but I genuinely don't know that I'll keep using it because of this.

  • Jade, your weight on your Strava profile was set to over 600 kg. I think that's very unlikely? I have changed your weight and Strava now calculates a touch over 1,000 calories. 

  • My running stats (with HRM) are ridiculous when synching from Garmin->Strava.

    Its a massive pain as I'm losing weight and I used to use Strava to synch to myfitnesspal (because the local pool "swimtag" only synchs to strava). But I can't any more because of this. It was fine until a few months ago and I get the same issue using two different watches.

    How much out - try 400 cals in Connect being translated as 5000 (yes thousand) in Strava:

     

    3.2 mile run:

    5865 in Stava (think that may kill me!)

    https://www.strava.com/activities/631917078

    369 (about right) in Connect

    https://connect.garmin.com/modern/activity/1243751937

  • I received feed-back from your staff and it is really appreciated.  I understand the algorithm you are using to calculate calories and I also understand the issues with all the different ways it is calculated, including issues with Garmin itself.

    The fact that the Garmin device may have issues does not mean the calculation formula you are using is any more accurate.  I realize it varies from person to person, but for me, I can tell you it is way off.  All of the data on both Strava and my computer are the same, weight, age, equipment, etc.  So the variables are what is used to do the calculations and how it is calculated.  

    One recent ride on flat ground where I was putting around with my wife and my HR never got out of zone 1 for example, Strava stated that I burned over 1,600 kcals on a 45 minute easy paced ride.  I actually burned about 300 kcals (actually only 100 over my basal rate.)  Strava overestimated my calories by multiple of over 5.  Yes, over 5 times what I actually burned.  

  • Yes Strava there's something wrong here. I just went for a 3.7 mile walk at 3.4mph average speed (took me about an hour). I'm about 13.5 stone and it said I burnt 607 calories.

    However last week I went for a 15 mile ride and averaged 16mph. It said I burnt 563 calories.

    The ride was a lot of effort whereas the walk was easy! Go figure.

  • Just to add another voice (and another person with diabetes) my disappointment at the wild overestimate of running calories. I use my calorie counts to monitor and balance my medical condition as well as physical hralth, so need at least a reason we assurance of accuracy.

    I was excited for the social and challenge aspects of Strava, but this is a glaring (and fixable) error that means I will be switching back to my old running app.

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