Different time spent in power zones in Strava and Intervals

[chung_fei_chan]

Hi,

Just returned from a 3 hour ride. What could be the reason of the discrepancy in time spent in power zones in Strava and Intervals.icu. There’s no difference in FTP set and the power numbers in the zones. The same discrepancy is shown in another long ride from a weeks ago.

[david]

Intervals.icu calculates time in power zones using a 5 second moving average of the power data. Power data jumps all over the place (is very noisy / spikey) which makes a mess of the zone times otherwise.