Originally Posted by
hamster
I have a puzzle of my own.
I wonder why Garmin and Strava disagree about my calories burned even with a power meter?
For the last 3 activities, Garmin Connect reports 994, 583, and 1654 calories. This is consistent with what was shown on the screen of the unit at the end of the ride.
For the same 3 activities, Strava reports 1279, 655 and 2136 calories. There's no apparent pattern.
* Activity 1: Garmin: 994, Strava: 1279, weighted avg power: 122 W, moving time: 3:07, avg speed: 12.1 mph
* Activity 2: Garmin: 583, Strava: 655, weighted avg power: 158 W, moving time: 1:15, avg speed: 13.7 mph
* Activity 3: Garmin: 1654, Strava: 2136, weighted avg power: 168 W, moving time: 3:29, avg speed: 15.4 mph
Trust the Strava data. For calculating caloric expenditure you should be looking at total work measured in kJ and multiplying by 1.0 or 1.1 to get calories. Weighted avg power is NP and not useful in calculating calories. I believe Strava uses a factor of 1.12 to go from kJ to calories.
Garmin connect doesn't calculate avg power properly and reports moving avg power excluding zeros which happen when coasting. Their total work seems to be accurate so you could just look at the work in kJ and use that number as calories. I don't know how they come up with the calorie number on their site (probably HR based) but it's not correct.