Category Enforcement - How is my category calculated? [February 2022]

yes those are the expected W’ values, but it makes more sense when you switch to watts or watts/kg and define some custom curves for various periods. As a reference my W’ is above 23000

Unfortunately Zwift seems to using Pavg for the estimation of your max intervals and that does in my view lead to a underestimation of your W’ which then lead to a higher CP. A good reference to the CP W’ theory can be found here:

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Has something changed with the calculation or is this just one of the quirks of the ‘new improved’ system.

I set power PRs through 3-13mins for the last 90 days in Tuesdays ZRL, and now CE has made a lower cat available to me? Seems an odd/broken solution…

I am low end B in ZP but I now have C available to me but Im sure when I raced on Monday I only had B cat available to me. Intervals.icu gave me an improved FTP(4 or 5 points from my 6:30 min effort) and also nudged my CP upwards,

Neither 60 day or 90 day timelines drop out any specific effort that might have caused it. No weight change etc

I doubt it, your CP probably just lowered because you set short duration PRs. Broadly speaking the steeper your power curve, the lower your CP. It makes physiological sense as a training metric (tldr: people with larger short duration power tend to have a shorter time to exhaustion at threshold) but not so much sense as a category metric

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Which kind of reinforces the thought its fundamentally broken to use it as a category system.

Get stronger in the areas that improve results (short power) then have low categories opened up to you as it drives CP down.

This is why pretty much every organizer is using both Zwift Category Enforcement and Zwiftpower Category override Wkg for results…to avoid the riders droping Critical Power under the limits with short term power.

Every event organiser bar zwift HQ?

I’m kind of on the fence with the ZP limits & CE, if CE works correctly it shouldn’t need ZP limits enforced… but a workaround is having to be applied to a broken system…

I could race in C legitimately but then get DQ for going over ZP limits which this whole change was meant to fix.

And then throw in the zwift watts threshold in the mix and it’s a shambles.

It works great for weeding out those 16/17min heroes but the failings in short range power has left it open to abuse and help those people who it’s meant to impact…

I agree…i already posted this months ago that it’s a problem.

Unfortunately riders with 20min W/kg above category limit treshold shouldn’t drop there CP below the limit that easy…but because of this we have to find other solutions.

The MAP factor is designed to solve exactly this problem, but Zwift have said they are not interested in lowering the threshold. So it is what it is.

I got bumped into A cat after tuesday wtrl race after improving setting new 90day pbs for 2:30min to 4:30min when going up titans grove and then my 7:30min to 8min power, set a 5min 90day power pb in the Friday hill climb which seemingly didn’t affect my ability to enter B races but now I have to get destroyed in A races due to an increase in short term power

Hi, does anyone know, if there were changes on the CE Algorithm lately? Some riders in my team got from B to A without any great new efforts.
Can i find the cp and map boundaries somewhere? And information about the calculation?
Thanks!

Scroll up in this thread it is there.

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Boundaries are listed at the top of this thread…

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If their sub ~3min power curve has lowered recently, that can cause their Critical Power to increase and potentially take them over the A threshold of 4.2W/Kg.

The original CP boundaries of 2.5, 3.2 and 4 W/Kg were increased around mid summer by 1.05, in order to give a similar “buffer” to the Zwiftpower categories using 95% of your strongest three 20min efforts.

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In our race series, we have a 3.48wkg 20min rider allowed to race C by CE…
3.48wkg in watts is above 200w for the rider.

If someone can workout how that equates to a sub 3.3CP I’d be grateful as getting queries from riders who are rightly miffed.

Currently it seems like CE is an incredible mess - started off on the potential right track but currently it’s a shambles.

Poor comms
Easy to manipulate
Confusing for end users
No transparency

@xflintx @James_Zwift can one of you take some ownership and communicate with the end users over this.

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Looking at the top of your B cat riders I think you probably need to look no further than the MAP performances they have put in during recent races.

From Flintx

Keep in mind that we originally published those values in February of this year (8 months ago) and have continually made changes based on user feedback.

Granted, we haven’t communicated every single one of those changes, and I understand how that isn’t the best.

I’ll personally make sure our documentation reflects this.

Here are the most current (as of today) values for open (men’s & women’s) categories:

I believe this is the most recent CE details posted on another thread by Flint.

  • A: 4.2 w/kg & 250W, 5.4 w/kg MAP (65 VO2)
  • B: 3.36 w/kg & 200W, 4.2 w/kg MAP (55 VO2)
  • C: 2.625 w/kg & 150W, 3.3 w/kg MAP (45 VO2)
  • D: Anything below C limits

And here are the most current (as of today) values for women’s specific categories:

  • A: 3.885 w/kg, 5.0 w/kg MAP
  • B: 3.36 w/kg, 4.2 w/kg MAP
  • C: 2.625 w/kg, 3.5 w/kg MAP
  • D: Anything below C limits

Note that for women’s specific categories, women do not have an absolute wattage value associated with their critical power (as is the case on ZwiftPower), and there is also no VO2 ml value.

Not easy to tell without looking at the rider.

I looked at your recent race but obviously don’t know if it was this one race or others.

1 or 2 riders stood out so all I can say is have you checked that the 3.48wkg 20 min is within the 60 day window. A couple of the best performers in your last race have good old history but not that much within 60 days.

it’s possible they were upgraded because a PR lapsed. ask them to retest their 3min max and see what that does for them

I can read & interrogate ZP as good as the next person, CE is becoming a bit of farce as the transparency just isnt there.

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Sorry I couldn’t help.

EDIT : could you explain your understanding of how you relate 3.48wkg 20 min to 3.3 CP. Do you consider FTP and CP are the same?

a very high short power widens the theoretical range over long durations, extreme examples include myself having 251w for close to 50 min in CE B at one point with a self calculated CP of like 245 or 247 or something. it’s physically possible, but it’s also stupid to base a category system on because when your short power is very high then your long duration CP becomes very hard to calculate accurately so it will take like an upper and lower threshold range and just split the difference, and the bigger your short power, the wider that range will be

someone who knows CP better than me can probably go into it in better detail. i only know enough to know that it’s stupid