# 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.

### 評論

81 條評論
• On my garmin  shows x calories, however when imported to strava it showns x / 1/2

1000 on garmin = 500 or 550 on strava

any idea why this is happening and more importantly do do you fix this?

• I’ve been wondering about this. It’s a while since I did A level physics but I can’t see how calories can be calculated without power data. On a bike surely gears are going to affect calorie output? Climbing up a hill in a big gear must use more calories than doing it at the same speed in a smaller gear? Can someone clarify the science/maths?

• Power output is independent of gearing, 300w at a high cadence uses the same calories as 300w at low cadence and you will be going at the same speed but in a different gear. So it is reasonable to estimate power from speed and incline. What you can't account for without a power meter is wind speed/direction or aerodynamics so there are some errors that will creep in there.

However, I have a power meter, and strava still consistently adds 10% onto my calories compared to both outdoor (stages power meter) and inside (tacx smart trainer) than what is reported by Garmin and Zwift.

That's just weird.

P.s. in the first paragraph I've ignored that there are certain cadences that are actually slightly more efficient than others - but differences with a "normal" range are negligible.

• why would my garmin at the end of a ride tell that i have burnt 1000 calories and when the import into strava is done strava tells me it is +_  500 calories?

• Garmin 936 calories versus Strava 281 calories (today)

Garmin 1038 C versus strava 230 (2 days ago)

Garmin 1053 C versus strava 271 C (4 days ago)

any idea why strava is showing allot less C based on the import from Garmin.

• I don't know which is more accurate, the Garmin 500 (with HR monitor) or the Strava entry for the same ride after it was auto-synced.

Just did a ride today that was 32.4 miles, avg. speed 16.7 mph (moving speed, not counting the time spent waiting for traffic lights). Avg. HR was 121 bpm (elapsed time was 2:03:34, moving time was 1:56:37, so 7 minutes wasted sitting at lights where my HR fell dramatically).

Strava calories: 1083
Garmin calories: 704

Bottom line is that I'm more inclined to believe that the Strava number is more accurate.

1) My HR data was skewed downward quite a lot by the non-moving time where I was stuck at stoplights. My HR during the ride was usually in the upper 120s to 130s every time I looked at it. There were around 7 minutes of non-moving time in a roughly 2-hour ride.

2) Garmin Connect reports my average speed as 15.7, because it doesn't calculate moving speed, just distance divided by the total time. It therefore uses an incorrectly lower average speed to calculate the effort.

I believe the Garmin data is skewed downward by this combination of lower heartrate average and lower average speed to yield a lower effort.

This isn't scientific, but in the past I've done a lot of exercise on a stairmaster at the gym. On this stairmaster one inputs one's age, sex, and weight, and it calculates calories burned, and stats like rate of calorie burn per hour. In the past I did a lot of stairmaster 30-minute blocks at various difficulty levels, and paid attention to my heart rate (the machine had those metal pads you hold to measure heart rate). Given similar heart rate levels I would assume roughly similar levels of effort, and hence calorie burn. The ~530 cal/hr calculated by Strava for today's effort seems fairly in line with calorie burn rates I saw on that stairmaster at the gym for stairmaster walks at roughly the same heart rate.

I have no idea what the real calorie burn is. It seems all of the calculators can be all over the place. I've used some online web-based calculators where you input sex, age, weight, distance ridden, and speed ridden, and gotten numbers like 2500 calories for the same ride as this one today. I'm pretty sure that's wildly inaccurate.

I guess the only way to get a truly (roughly) accurate calorie burn calculate is to put a power meter on the bike. I may end up with a Stages left-only power meter for Christmas or something. I'd really like to know what I really burned.

• Strava versus Amazfit:

522 kcal vs 219 kcal (238%)

275 kcal vs 140 kcal (196%)

437 kcal vs 197 kcal (221%)

586 kcal vs 280 kcal (209%)

391 kcal vs 203 kcal (193%)

662 kcal vs 353 kcal (188%)

234 kcal vs 155 kcal (151%)

358 kcal vs 200 kcal (179 %)

I mostly do quick walks for fat burning, some short jogging and walk-jog mixes. The difference between Strava and Amazfit are huge - especially with walks (about 6 kmph). I'm not saying that the Amazfit app is perfect; it probably underestimates energy consumption but come on, 200% difference with two professionals is not normal.

• Hi, I realize this is a 'Zombie' and likely won't get any attention. Apparently I am burning 10's of thousands of calories per long run. For instance:

That was a short ramble up a hill and around some trails.
This happens on every activity. It is like it's multiplying the actual number by a factor of 100.

Here's some slow HR training:

10,000 Calories while maintaining a 135-140 HR. Shouldn't I be dead?
Thanks....

• Haha! @ellie. Damn, OOPS! Thanks for that. :)

• Whilst I'd like to see the calorie estimation improve in accuracy I doubt it could ever satisfy everyone simply due to wide ranging efficiency differences between people. I have determined my own ratio to Strava numbers (e.g. 60%) based on analyzing weight & food intake etc over time and now just go with that. Just watch different people running or cycling and you can see how efficient/inefficient some people are, and a calorie calculator will never account for that - It will always be for the "average" person.

• For most runners of a given sex, height, and weight there are only minor differences in efficiency. So accurately calculating calories based on an average athlete would be fine for most of us. At least it would be better than the current numbers which are a bad joke.

• Re: Kevin Beyer I don't use Apple or any other apps LoseIt connects to directly. I started entering the runs manually, which is a bit of a pain but manageable. It's just a shame Strava can't get their act together on this.

Those are differences I got on one run between three different apps:
Strava: 1,665
LoseIt: 1,285
Garmin: 1,323
The variance between LoseIt and Garmin is negligible. The variance between Strava amounts to 25% on Garmin side and even higher with LoseIt! That's ridiculous.
(All apps have the same parameters.)

• I've only used Strava (free account) 3 times, but I'm also frustrated about the apparent miscalculation on Kcal !

Used to be on NRC and Apple Training. Both suggest around 64 Kcal / Km. Strava is slightly over 100 Kcal / Km !

Seems to be a long standing issue, that must be solved !

Otherwise I'm very positive :-)

• I have the same inaccuratcy issue with Strava.

I have been using Apple watch 3 workout app for a while, today is my first time switch to Strava app on aw3 and immediate some differences:

Distance: AW3 10.8km / Strava 10km.

Active Calories burned: AW3 ~ 570cal / Strava ~ 930cal (wow, easily hit 1,000cal/day)

Time: Actual running time: 1:11:12 / Strava: 1:08:51 (autopause issue, I turned it off right after the run)

Pace: aw 6’38” per km / Strava 6’53” per km.

I will switch back to aw workout app and use WorkoutMerge app to transfer the workouts to Strava to connect with my friends.

• What I don't understand is when I cycle with a heart rate and power meter, Strava shows my power output at 1200 kJ (recent ride example). The description for this "Total Work" metric is, "Total Work, expressed in kilojoules (kJ), is simply the sum of the watts generated during your ride. There is a close 1–to–1 ratio with Total Work and Calories expended during a ride."

Why then does Strava show my "Calories" as 1715? Please address this issue. The calories number should be as correct (i.e. as accurate as possible given all available data).

• Either garmin or strava have changed something recently because now I get identical calories on both garmin connect and strava on rides using a power meter and garmin head unit... so either strava now pulls the calorie figure from garmin or (hopefully) they now both use the same calculation to determine calorie burn.

• yeah it's pretty off. without any tools, just logging a recovery walk, it claims i burned 1300 kcal, but a walking burn calculator shows around 970 Gross, 730 Net. https://www.strava.com/activities/2228689435

• BTW, here is the ride on Strava: https://www.strava.com/activities/638679011

Here is the same ride on Garmin: https://connect.garmin.com/modern/activity/1253031885

And to show you it was a moderate pace ride for me where I did not even put in a full effort, you can see that there are no PRs and nothing close to any personal bests for me on any segments of this ride.  I have done these routes hundreds of times and hold the KOMs on some of the sections.

• 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.

• I don't see the problem.  Every jog I burn about 4000-5000 kcal, so I then go to the buffet and replenish calorie for calorie.  I'm gaining weight but it is all muscle.  It all seems to check out just right.   Strava is spot on!

• I'm new to Strava and I've also discovered that it seems like Strava underestimates my calories burned. If the  calories are not underestimated then there is absolutely no point in exercising. I rode for one hour last night at an average speed of 11 miles per hour. It said that I burned 180 calories. My problem with this is that I could sit at my desk all day and burn 122 calories per hour. If I stand, rather than sit, I go up to 163 burned per hour.

How is it possible that all that huffing, puffing, sweating and wheezing only nets me about 17 more calories per hour? The calculations are wrong or this is very discouraging.