Incorrect power meter data

[erlendostbye]

I have a 4iiii power meter, and i have discovered that there is a discrepancy between the average power i displayed in Garmin Connect and Strava. On my last ride Garmin claimed 223W, while Strava claimed 167W (Not too big numbers... hehe). That 56W in difference. I have checked that the power meter is registered, and that Strava does not estimate the power. Does anyone know how to fix this? 

[Jane · Accepted solution]

Hello @erlendostbye 

Thanks for posting about this and apologies for any confusion.

Weighted Average Power is similar to - but NOT the same as - Garmin's Normalized Power.
Both numbers attempt to capture the average effort of a workout by taking into account lactate accumulation and other types of fatigue. Strava uses an algorithm very similar to xPower for computing Weighted Average Power.   Find out more here. 

There will be differences between the Weighted Average Power and Normalized Power. How much and which direction will depend on the ride. Typically, for shorter rides, Weighted Average Power will be lower than Normalized Power.

This is a result of the different types of smoothing used by the algorithms. Both numbers have been used successfully by professional coaches.

Another thing to keep in mind is that on Strava we do not remove any sections of zero power from your data before we do our calculations.  Whether or not your Garmin power calculations are including sections of zero power depends on your Garmin settings.  You can check the Garmin Support site to find out how to adjust this setting if necessary.

I hope that provides some insight into this.  Please let us know if you have any further questions.