How does Strava calculate % Intensity?

Coach Rich

I've set my FTP in my Garmin and on Strava to be the same. Finished the hard portion of my ride today with .975 IF for ~54' #backdoorbrag. IF dropped to .91-.92, per the Garmin, by the time I got home, as it's mostly downhill. 

Uploaded the file into Strava and it gives me 87%. I wants my 4% back!!

#cantbebotheredtoGoogle

rlh2000

Sorry Coach, with that hashtag I couldn't resist:

http://bit.ly/1pHey2D

RHolmes

Ok Rachel...that is awesome! I need to know how you did that!

Swanie

Where strava gets out of line is, intensity is based on "weighted average power" this is Stravas version of normalized power and its calculated way too low. A good ABP ride the other day was .811 IF and 235 NP on my Garmin and strava gave me .72 IF and 209 WAP. I can't find any way to adjust how WAP is calculated.

Coach Patrick

There's also this...it compares your performance in a segment to your power in the previous six weeks....so according to this blog post, not only is Coach Rich too lazy to use google, but maybe he rode that segment harder in the last six weeks? http://blog.strava.com/segment-intensity-score-5620/