Option to use accumulated power for calculations

[Pieter_Bartlema]

As mentioned in the topic below, there are discrepancies between the power values shown on Garmin Connect and Intervals. Most likely, this is due to differences in the calculation methods. Garmin uses accumulated power (work) over time as the basis, whereas Intervals uses the instantaneous power value recorded for each second.Please see the topic below for more details.

Difference in average power (and normalized power) between Connect and Intervals

Hi David, Did you already had a closer look? I noticed that all my ride activities on intervals give somehow lower power values than Garmin does. For example yesterday activity (lap button pressed once the race started, total lap time: 1h12m): 273w average and 295w normalized. While Garmin gives 288w and 309w. The Garmin values are also the same values that I saw on my bike computer during the race, therefore I tend to think the Garmin values are ok and that somehow Intervals is going funky t…

I would like to be able to choose the preferred method, hence the request for an option to use accumulated power for calculations.

[R2Tom]

Is that Garmin or PM specific? I don’t see accumulated power in my fit file recorded with Wahoo?

[app4g]

AFAIK , accumulated values basically tries to account for dropouts at the headunit level. Internally, the PM will keep a running total. And you’re also right that not all head units will have it.

[Pieter_Bartlema]

@David, could you please share your thoughts on this?
Correct handling of the power data is fundamental to all further metrics.

[Rohan_Christmas]

Is there a lot of RF interference in the locations that you are experiencing this? If not maybe your power meter or Garmin are problematic.

[david]

I will have a look at this when we have finished the huge web app library upgrade we are busy with. It would be very nice to have Intervals.icu power numbers match Garmin’s as this generates a lot of questions. However it is also a big change and it is quite irritating that the second by second numbers Garmin writes to the file do not match the “accumulated power”.

[Nik_Om_Cinderella_Ri]

seems like Accumulated Power is only useful for calc the Normalised Power and Averages. Which I believe should already be what is used when Garmin Writes it into the FIT File as SESSION messages?