Check out the power curve at the bottom of the post, it's composed of two screen caps from the same ride, stacked on the same image:
Apparently on the ride in question the cyclist rode at:
- 291W for 12min 55s
- 270W for 9min 10s
But I would have though that if you rode for 291W for 12min 55s, you also rode at least 291W for 9min 10s ... right? ... 🤷♂️
What are these dips? How are we meant to interpret this data?
I would expect power curves to either be flat (usually a result of ERG mode on a trainer) or constantly falling as the time period increases.
I reached out to Strava and their facebook rep said it was 'complex' and to send in a query to the support email - they haven't replied.
I had a look here: What method or algorithm is used for computing Power Curve on Strava?
It's good info, but the example given there doesn't have a dip, and doesn't discuss it - but it does make make me think that the answer might just be what I'm trying to avoid suggesting...
Addressing some of the comments:
At a casual glance I'll agree that power curves do show power plotted against time, but don't be mistaken in to thinking that they show instantaneous power over time.
Power curves show the maximum power a rider rode for a duration (averaged via various means, some algorithms more clunky than others), and as has been confirmed to my satisfaction they should be a 'monotonically decreasing function of duration' - but they're not on Strava, (which prompted my original query...)
Here is a visual example of how power curves are different from power with respect to time:
Instantaneous power over time:
Power Curve plot from the same data:
- They are under different sections in Strava
- They don't look alike
- The 418W at 1 min on the power curve correlates to the 1 minute duration that 418W was held (around the 21min 40s period seen in the instantaneous plot and not 1 minute in to the ride)
- The power curve has a logarithmic time scale