Difference between lap-power and time-interval

[Torsten]

Today, I was out for a short bike-ride for doing some intervals.

Avg-power, as stated by Garmin:

lap2: 316 W (5min)

lap4: 322 W (5min)

lap6: 403 W (1min)

lap8: 432 W (1min)

So I imported the workout using Strava into Golden Cheetah and was a little bit surprised:

a) When it comes to avg-power, the lap-values shown by Golden Cheetah are much lower.

BUT (!)

b) The avg-power values that are subdivided as per time-interval (1, 5, 10min...) seem to fit, as 5min is @ 321W.

Is that a bug or does it work as intended? :-)

Please find my picture attached.

OS: Mac OS 10.13

GC Build: 3966

[drno...@gmail.com]

Hi guys,

digging a little deeper I have discovered that the 'lap' times are off - which is what skewes power data when doing interval training.

By comparing a FIT file (taken directly from Garmin) and Strava download here is what I have found.

Correct lap times from a FIT:

        "INTERVALS":[
            { "NAME":"Lap 1 ", "START": 0, "STOP": 1584 },
            { "NAME":"Lap 2 ", "START": 1584, "STOP": 1945 },
            { "NAME":"Lap 3 ", "START": 1945, "STOP": 2548 },
            { "NAME":"Lap 4 ", "START": 2548, "STOP": 2909 },
            { "NAME":"Lap 5 ", "START": 2909, "STOP": 3365 },
            { "NAME":"Lap 6 ", "START": 3365, "STOP": 3726 },
            { "NAME":"Lap 7 ", "START": 3726, "STOP": 4195 },
            { "NAME":"Lap 8 ", "START": 4195, "STOP": 4556 },
            { "NAME":"Lap 9 ", "START": 4556, "STOP": 5008 },
            { "NAME":"Lap 10 ", "START": 5008, "STOP": 5377 },
            { "NAME":"Lap 11 ", "START": 5377, "STOP": 6550 }
        ],

Incorrect times as synched from Strava (same activity):

        "INTERVALS":[
            { "NAME":"Lap 1 ", "START": 0, "STOP": 1581 },
            { "NAME":"Lap 2 ", "START": 1496, "STOP": 1858 },
            { "NAME":"Lap 3 ", "START": 1860, "STOP": 2463 },
            { "NAME":"Lap 4 ", "START": 2464, "STOP": 2824 },
            { "NAME":"Lap 5 ", "START": 2825, "STOP": 3281 },
            { "NAME":"Lap 6 ", "START": 3279, "STOP": 3639 },
            { "NAME":"Lap 7 ", "START": 3642, "STOP": 4110 },
            { "NAME":"Lap 8 ", "START": 4111, "STOP": 4471 },
            { "NAME":"Lap 9 ", "START": 4472, "STOP": 4924 },
            { "NAME":"Lap 10 ", "START": 4923, "STOP": 5291 },
            { "NAME":"Lap 11 ", "START": 5291, "STOP": 6460 }
        ],

It appears as there is a bug when downloading data from Strava.

Looking back at my data - I have discovered that the bug goes as far as March 2018.

Last correct file synched from Strava was 26th Feb.

I usually use latest DEV build so I am assuming that version released sometime after end of Feb has a bug in it.

Hope that helps.

Unfortunately I don't have skills to dig into the source code.

Cheers,

Peter

Dne petek, 25. maj 2018 07.23.41 UTC+1 je oseba Torsten napisala:

[Mark Liversedge]

Strava is the source of this problem.