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Calories No longer correct

S

SegRat

macrumors newbie
Original poster
Dec 27, 2011
29
53
My watch series 6 suddenly is showing far less calories burned during workout. My 5 mile treadmill runs would show me burning 600 - 700 calories. The last 2 weeks it now says the same runs are high 400's, low 500's. My miles are also off by close to 1 full mile.

I did a 20 mile bike ride yesterday. I have done this route multiple times. Calories burned always ranged 900 to 1000. Yesterdays ride shows 705. However the milage is correct.

I have tried recalibrate, and I also unpaired and repaired my watch. I see nothing online recent that shows others are having this issue. Any Idea's?
 
I experienced this issue with my Apple Watch series 5 during my Swim workouts. I did the same thing every day and some days it would say 500 calories burned others 300 calories burned. I don’t know what causes the discrepancy.
 
Had a similar thing happen to me with my Apple Watch and the Fitness app.

My daily caloric burn was ~20% lower than what it has been (with all other factors equal).
 
I've had this intermittently. I think it's something to do with the heart rate sensor stopping taking readings mid-workout. I recall one workout in particular where my calories burned remained stuck at 750 calories or something for like the last ~20 minutes of my workout.

forums.macrumors.com

Heart Rate Monitoring Gives Up After Awhile During Workout

I've been noticing about 40 minutes into my cycling workouts the heart rate monitoring seems to just stop. Example here from yesterday where about 40 minutes into the workout it stopped reading my heart rate for about 5 minutes (I can tell when it stops because my calories burned stops...
forums.macrumors.com forums.macrumors.com
 
sixtydashone said:
I've had this intermittently. I think it's something to do with the heart rate sensor stopping taking readings mid-workout. I recall one workout in particular where my calories burned remained stuck at 750 calories or something for like the last ~20 minutes of my workout.

forums.macrumors.com

Heart Rate Monitoring Gives Up After Awhile During Workout

I've been noticing about 40 minutes into my cycling workouts the heart rate monitoring seems to just stop. Example here from yesterday where about 40 minutes into the workout it stopped reading my heart rate for about 5 minutes (I can tell when it stops because my calories burned stops...
forums.macrumors.com forums.macrumors.com
Click to expand...
Good to know
 
I had the opposite. I was doing yard work and a couple of bike workouts somehow I ended up with the move ring showing 54,941.
 
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I moved on from Series 1 for this reason. My morning workout is the same on the treadmill - 60 minutes at 4.8 miles and 10 minutes at 4.5. Calorie range was 840-860 and suddenly dropped to 500-600. Tried multiple fixes that were suggested and all to no avail. I have a series 5 now and things are more consistent. It did drop a little more than expected at one point and I used the Reset in the Watch App. That seemed to help. I notice the change most when there is an update.
 
SegRat said:
My watch series 6 suddenly is showing far less calories burned during workout. My 5 mile treadmill runs would show me burning 600 - 700 calories. The last 2 weeks it now says the same runs are high 400's, low 500's. My miles are also off by close to 1 full mile.

I did a 20 mile bike ride yesterday. I have done this route multiple times. Calories burned always ranged 900 to 1000. Yesterdays ride shows 705. However the milage is correct.

I have tried recalibrate, and I also unpaired and repaired my watch. I see nothing online recent that shows others are having this issue. Any Idea's?
Click to expand...
I have had an ongoing issue with calories estimated by the workout app. I have found one factor that seems to have an effect - one that I can replicate at will. This will likely sound impossible but I have found that if I am carrying my iphone during outdoor walks or runs the watch will determine that I expended less calories than if I did the same workout without having my iphone nearby. The shortfall in calories shown by the workout app is correlated with the intensity of the workout. For more intense workouts the shortfall can be as much as 40%. For gentler workouts the shortfall will usually be in the range of 10% to 20%.

This issue has been with me through three generations watches (2,4,6) and two generations iphone (6S and 11). BTW, I started collecting results with screenshots from my iphone Activity app, and have a nice collection of pairs of identical workouts, one of each from exercise without my iphone, the other with my iphone.

I have started making progress on this issue with Apple support several times, but then the reps who had assured me that they would see this through have become unavailable. At which point I have had the opportunity to start the process over again. I finally gave up when, for reasons that my Apple support person could not figure, we could not upload logs of my activity.
 
SegRat said:
My watch series 6 suddenly is showing far less calories burned during workout. My 5 mile treadmill runs would show me burning 600 - 700 calories. The last 2 weeks it now says the same runs are high 400's, low 500's. My miles are also off by close to 1 full mile.

I did a 20 mile bike ride yesterday. I have done this route multiple times. Calories burned always ranged 900 to 1000. Yesterdays ride shows 705. However the milage is correct.

I have tried recalibrate, and I also unpaired and repaired my watch. I see nothing online recent that shows others are having this issue. Any Idea's?
Click to expand...
Just so you know, heart rate is taken into account for workouts and calorie count. The more you do an exercise, the better adept you become at performing it, and hence the less energy it takes which means you burn less.

The watch is not wrong in that aspect. As per the mile being off, that's a GPS issue. Try doing it again to double check.
 
I have checked this many times, and know that heart rate is taken into account. When I do the same workout twice (in one day or over a two day period, so a conditioning effect is not relevant) I see almost the same distance, the same speed, the same heart rate, the same elevation gain. And yet the calories differ, often by a lot.

I did not say that the mile was off.
 
Seabreeeze said:
I have checked this many times, and know that heart rate is taken into account. When I do the same workout twice (in one day or over a two day period, so a conditioning effect is not relevant) I see almost the same distance, the same speed, the same heart rate, the same elevation gain. And yet the calories differ, often by a lot.

I did not say that the mile was off.
Click to expand...
Are you OP?
 
I don't know what OP means. Original poster? No, I am responding to someone else's post. But I did start a thread on this several months ago, but didn't get much response.
 
To illustrate, here is one set of several sets that I sent to Apple support

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I recently did an experiment where I performed an hour long workout, wearing two chest straps (by Polar and Wahoo) and the Apple Watch. Loaded all three results and everything was generally the same with very minor variations. The only major difference was the AW calorie count was way off by about 30%. Virtually the same data, HR monitor was fine, but the count was off. I double checked by health stats and my weight/age/height were all the same.
 
Another thing I would add in general, is that the AW is not meant to be 100% exact as it uses logic, accelerometer and heart rate to calculate plausible calorie burn count.

I have always used the AW calorie count as a good average or approximate count.
 
jav6454 said:
Two separate instances are not representative. Not minimizing them; however, several factors are involved.
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I understand that. I have sent six sets of these to Apple. And one of my Apple Support people told me that there is definitely an issue, and that engineers were exploring it.

One other tidbit of note in the screen shots I sent. Note that the two screen shots, which in my understanding are shots of a standard report, have an interesting difference. The screen shot of the workout when I was not carrying an iphone includes a field called "Elevation Gain." The screen shot when I was carrying my phone did not include this field. So a standard report apparently is not quite standard.
 
jav6454 said:
Another thing I would add in general, is that the AW is not meant to be 100% exact as it uses logic, accelerometer and heart rate to calculate plausible calorie burn count.

I have always used the AW calorie count as a good average or approximate count.
Click to expand...
But a 30% - 40% difference that I can replicate at will? That is a fair amount off from being less than 100% accurate.
 
jav6454 said:
Another thing I would add in general, is that the AW is not meant to be 100% exact as it uses logic, accelerometer and heart rate to calculate plausible calorie burn count.

I have always used the AW calorie count as a good average or approximate count.
Click to expand...
P.S. Sorry to react like I am. You can see my frustration. The "iphone discount," as I call the difference in calories for the same workout, overwhelms any value I might get from a calorie tracking app.
 
Seabreeeze said:
P.S. Sorry to react like I am. You can see my frustration. The "iphone discount," as I call the difference in calories for the same workout, overwhelms any value I might get from a calorie tracking app.
Click to expand...
I understand, which is why I telling you an AW is not a device for exact calorie count. After all, it doesn't measure calories, it provides a guesstimate.
 
My belief, though, is that an iphone somehow interferes with the calorie estimates made by the Workout app. Each new Apple rep has told me that this is not possible. But pretty much every one of them has concluded, based on my ability to replicate the issue, combined with the missing elevation gain field, that there is a real issue here that might be more substantial than a slight mis-guesstimate.
 
SegRat said:
My watch series 6 suddenly is showing far less calories burned during workout. My 5 mile treadmill runs would show me burning 600 - 700 calories. The last 2 weeks it now says the same runs are high 400's, low 500's. My miles are also off by close to 1 full mile.

I did a 20 mile bike ride yesterday. I have done this route multiple times. Calories burned always ranged 900 to 1000. Yesterdays ride shows 705. However the milage is correct.

I have tried recalibrate, and I also unpaired and repaired my watch. I see nothing online recent that shows others are having this issue. Any Idea's?
Click to expand...
Getting better and using less energy? I noticed this when I first started doing Apple Fitness CORE and HIIT workouts...as I repeated a workout the amount of calories burned decreased.
 
Blowback said:
Getting better and using less energy? I noticed this when I first started doing Apple Fitness CORE and HIIT workouts...as I repeated a workout the amount of calories burned decreased.
Click to expand...
While that is true (over time), the best experiment is to wear multiple HR monitors and compare the results.
 
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