The first category enforcement test races on Zwift were announced in late February, and the initial test was a success by anyone’s definition. For the first time in Zwift’s history, riders were restricted in their choice of race category based on their historic power data.
Since those early trials, Zwift’s category enforcement tools/features have been evolving, as has their documentation.
Today, with many positive reviews from community members, category enforcement is being used in more and more races each week. Currently there are 623 races happening in the next 7 days, with 145 of those races using the new category enforcement tools. Category enforcement is an option for event organizers to use on request, but it is not yet the default.
Next Steps
I reached out to James Bailey (originally a Zwift community member and now working at Zwift as an Event Operations Specialist) for an update on category enforcement. Here’s what he told me:
We currently have 15+ organisers with approximately 185 events running Category Enforcement. This assigns an estimation of critical power (CP) from looking at the Zwifters 2-50 minute power curve. This determines their category based on both CP and MAP using the below values:
- A: (4w/kg CP OR 5.4w/kg MAP) AND 250w CP
- B: (3.2w/kg CP OR 4.1w/kg MAP) AND 200w CP
- C: (2.5w/kg CP OR 3.9w/kg MAP) AND 150w CP
Whilst not quite “fully baked” the feedback we have received from the vast majority of users who have taken part in Category Enforcement races has been extremely positive. A large number have said how much more enjoyable they have found racing and how their events haven’t been stretched early on by riders who shouldn’t have entered that category.
Prior to promoting outside of the Futureworks banner there are a number of areas that we need to work on. These include:
- Category Enforcement in Women’s races
- Support material explaining how CP and MAP are calculated.
- Better integration and visibility in ZwiftPower and minimizing discrepancies in category sign ups
- Ability for Event Organisers to customise limits
Additional Next Steps
On the “Next Steps [February 2022]” forum post, James shared that the goal is to make category enforcement the default setting for Zwift races, so organizers would need to turn it off on purpose. But before that happens, Zwift has a short list of things they want to get in place. Here’s what James listed on the forum thread:
- Riders without data automatically go into E (rather than A)
- Better information presented when signing up for an event, rather than just being told that you can’t
- Ability for Support to “forget” an effort when it’s been caused by a miscalibrated trainer, or similar
- Adding CE for Women’s races
- Support documentation that isn’t “ask James or Flint”
Critical Power
The use of Critical Power (CP) instead of FTP is an interesting move, and one that will have reverberations throughout the cycling world just as Zwift’s focus on FTP has made it a more prominent metric. While CP and FTP are sometimes used interchangeably, they’re actually two very different metrics.
CP and FTP are typically within 10% of each other for any given cyclist, but they are calculated using very different inputs. An explanation of CP is outside the realm of this post, but you can check out this BikeRadar post for a more in-depth look at the Critical Power metric.
If you don’t know your CP, you might check out intervals.icu as a free service that can calculate your CP and many other metrics. Tip: find your CP by going to Power>Options, and choosing “Morton’s 3 Parameter CP” as the “power model used to estimate FTP”.
How does CE actually work?
To put it simply: Zwift looks at your last 60 days of activities to determine your minimum category. That’s the essence of category enforcement as it currently stands.
As often happens with early-stage projects, there was very little documentation available for category enforcement when it was originally trialed. One Zwifter (James Eastwood) pushed Zwift hard for more details, then put together a thorough post explaining how category enforcement works – or more specifically, what the Critical Power (CP) and MAP/VO2 category boundaries are, and how those are calculated.
If you’re wanting to dive deeper into Zwift’s use of these metrics for category enforcement, read James’ post.
Finding Category Enforcement Races
Zwift has no easy search filter built into Companion, etc to list only those races using category enforcement. But ZwiftHacks, as always, comes to our rescue! Here’s a custom ZwiftHacks search showing all upcoming category enforcement races.
Questions or Comments
Have you tried category enforcement races yet? How was your experience? Share below!
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