What happened in this race?

Thanks for your clarification. I appreciate that no system is going to be perfect and there will always have to be riders at the top and bottom of every category. I am actually quite proud to manage to get into Category A at my ripe old age.

What I would argue, is that most Zwift races are between 20-60 minutes and won by riders with very strong 3-5 minute performances. Therefore would it not make more sense to put more weighting onto these shorter efforts when deciding Category Enforcement?

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O yes that is true, I have been At the bottom and top of every cat (D to B), working hard to be bottom A.

But that should not be the driver for Zwift to simplify the system. There will always be people gaming the system, and if we start to see them complain then we know the system is working.

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We already do that with the introduction of zMAP into the rules. If we use even shorter durations below 3 min. it will make things even more confusing and possibly unfair.

Is this a change? At least there are a lot of past recommendations, and anecdotal success stories, of success lowering zFTP scores by doing short duration maximal efforts?

At one point you also wrote this, but I could be misreading what it’s implying?

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No, it was not a change. Most likely just anecdotal success stories.

At one point you also wrote this, but I could be misreading what it’s implying?

I didn’t explain it correctly so I’m sorry for that. On the backend we create a complete “power profile” from sprint, anaerobic and aerobic capabilities. So to have an accurate/complete power profile you should do efforts (maximal) in that range. It doesn’t mean that zFTP uses that complete range to be calculated…

Ok, but if you have an ‘incomplete’ power profile because you don’t have any maximal efforts of short duration, then doing short maximal efforts will complete your power profile and could(?) and likely would (?) change your zFTP score?

No, it won’t

Before and after examples – 20 watt difference in zFTP

Thank you, and you clearly have a better understanding of the system than I do.

This isn’t me complaining that I’ve been unfairly placed in Cat A, I’m not good enough to win Cat B races, so it’s of no concern to me, and exciting to compete against the very best. It’s more a case of lets bring the guys that podium in nearly every Cat B race that they compete in up into Cat A too. I presume that it’s similar in C & D too, but I’ve never competed in these Cats so am not as familiar with the riders at the top of the rankings. It might also mean we see more equal field sizes in categories A , B & C although presumably D would decrease.

I appreciate that this is most probably very difficult to achieve without a points based system, and there will always be people gaming the system. I don’t want this to come across as a negative post, just as one by someone that loves racing on Zwift and wants to help Zwift continue to improve. It could be that my opinions are out of step with the vast majority of Zwifters, and in which case I’m happy to sit down and shut up :slightly_smiling_face:


I reckon the number of D participants would increase if this category didn’t include such a huge range of ability, lots of D racers aren’t racing because they feel they have absolutely no chance of keeping with main group.

Riders will get a zMAP promotion to C if the model predicts they can do 3.3W/Kg+ for 6mins and their zFTP is over 150W.

It would help if there was a raw Watts threshold to zMAP, something in the 260-275W+ rough ballpark. There’s a number of D riders who can do over 300W for 5mins, in a category that heavily favours flat races over mountains.

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This is almost exactly what happened to me. I did a ~12 minute race and zFTP went from 235 to 257. I followed up a few days later with a ride that included only a warmup and a 3 minute effort. zFTP went back to ~235. Exactly why it happened is only my conjecture, but it seems about as clear as it can get without access to the data and exactly how it was used. Prior to that I had never attempted a 3 minute max effort.

That clearly is a case where the 5 to 8 min. range comes into play. Not the 3 min. power.

ahh ok. So you’re saying that anything less than 5 minutes on one’s power curve has no impact to zFTP? In @Paul_Southworth mention just above, it’s then likely that his warmup plus 3 minute effort led to a higher 5 minute average than whatever his previous 5 minute value was?


it’s then likely that his warmup plus 3 minute effort led to a higher 5 minute average than whatever his previous 5 minute value was?

Most likely

According to TrainingPeaks, I did not set a 5 min PR during this period when my zFTP was elevated. I went from C to B on 11/30/2022. I believe I went back to C after the Volcano Climb ride on 12/13/2022 that included a 3 minute PR but not a 5 minute PR. My next CE event in C was 12/14/2022 so by then I was a C again. That matches my recollection of what I saw on my profile for CE data: a 3 minute PR but no others between 11/30/2022 and entering the race on 12/14/2022.

It would certainly clarify things if I could view history of my PRs used by CE.

I have improved all my performance from 30 seconds to 5 minutes, although my 12, 20 & 30 minute efforts are the same. My zFTP has gone down zMAP has stayed the same and VO2 max has gone up. I have now been downgraded to Cat B.

Judging by what I have been told improving my 5 minute power by 2 watts has resulted in the downgrade.


Good work on the downgrade.


I know David said that <5 mins doesn’t count but I’d be more inclined to believe that 3 min bump was the cause…

Congrats on giving the algorithm better data to base it’s calculation upon. :grin:

3 through 12

Is it 5 mins or not?

Or is it just another broken categorisation system?