Duration estimates awry

Hi David:

An intriguing thing had occurred. I did a 1:15 hr workout, recorded on Wahoo and uploaded to Strava and thence to intervals.icu. Here is is: Intervals.icu.

Strava has determined that the ride is 32m long. When I go to analyse the activity, I see that the duration given in the top left of the screen is 32:01m: fair enough, just like Strava.

But the graphs under that – Power, 30-sec power, Hr, etc all have duration going to 1:13:24 hr. So two things going on here:
[1] discrepancy between the duration of the ride as shown on all the graphs and the duration as reported in the summary at the top of the /activity page;
[2] the duration as reported on the graphs is different from that recorded by Wahoo [1:15:05 hr] and uploaded to TP.

Is this a bug? A problem with the file from Strava? An idiosyncratic feature associated with Cape Town? Your help would be greatly appreciated.

Snd, as always, thanks for your work on this site.


Intervals.icu uses the moving time from Strava because people are happier if Intervals exactly matches Strava. Strava provides a “Moving” stream that you can enable on the ride timeline chart:

As you can see a lot of the time you were not moving and the distance ruler is also off. Was this an indoor ride?

Yes, on the trainer with no speed sensor. Does this mean that I need to put a speed sensor on my wheel?

If you don’t have speed sensor on your bike, speed must come from your trainer. You probably have drops in signals coming from your trainer, but then I would expect drops on power too, unless power comes from a power meter on the bike.
Another possibility is that speed comes from your GPS signal, but that’s rather unlikely in this case. Anyway, make sure GPS is off and check sensor signals from the trainer. I find it more usefull to eliminate speed completely. Intervals has no problem with workouts without speed/distance. I do that all the time.

Dumb trainer on this occasion: Kurt Kinetic Road Machine, with Assioma power pedals. So no speed dats, but power from the pedals.
Speed therefore has to come from the GPS – the “map” shows small apparent movements within a town block.

The problem I have is that intervals.icu has the nominated duration for the ride [top left of the /activity page] wrong; and different from the duration that is shown [almost correctly] on the graphs on the /activity page. Therefore:
[1] there is a disconnect between the summary data and the detailed graphs within intervals.icu; and
[2] when I come to the /compare page, training duration data are therefore wrong.

Use FIT File Tools to strip speed and distance (eronous GPS data) from the fit file and reimport the resulting FIT file.
Make sure to deactivate GPS the next time you ride indoors!

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I have an intervals profile on my head unit and Forerunner watch. It’s set (as default) to have the GPS off, compared to the other profiles that are GPS on. For a number of years I had workout data with zero distance and elevation.

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