On S3, I usually burn 450-530 ACTIVE kcal during a 45-50 min HIIT exercise, with avg. heart rate varying between 136-142.
Then I bought S4 and the first time I used it, I got similar results as with S3.
But then I decided to reset calibration data and calibrate the new clock because, well, it's a new clock so I wanted to do the correct calibration. (I did two 20-minute outdoor trips in workout out as it was suggested by Apple to calibrate the clock).
After that, the next time I did a similar HIIT exercise as before, only 167 ACTIVE CALK (!!) Is tracked in 50 minutes. How could it be possible? This is far too low. Heart rate was tracked in order, no holes. Ranked. heart rate 1
Today it was 2nd time after resetting calibration and the results after a similar HIIT exercise were slightly better: it showed 296 ACTIVE kcal burned. Ranked. heart rate 140.
However, this is still less than before I reset the calibration when it logged 450-530 ACTIVE kcal during exercise.
Could it be that the clock is still learning? and that after some more workouts will it show kcal correct again? Please inform.