On Zwift, speed is determined by two major inputs: body weight and power output in watts. The two inputs are commonly expressed in-game as a a single metric: watts-per-kilogram (w/kg). To put it simply, the higher your power output per kilogram of body weight, the faster you will go. This means if a racer artificially lowers their weight or uses a power source which inaccurately inflates power output, they will get a substantial benefit in races. Since racers enter their weight on the honor system in-game and power source is completely up to the racer, there tends to be a lot of skepticism when it comes to racer performance.

The Beginning

In 2016, a community policing initiative known as the Zwift Anti-Doping Authority (ZADA) was started to oversee Zwift races. The group took it upon themselves to verify racer performances; awarding racers who passed verification with a “ZADA-approved” badge on ZwiftPower, and suspending riders found to be exploiting faulty power output or weight. The group’s mission was “to have an objective, impartial review of whether someone’s performance is plausible”. Although far from perfect, ZADA kept the peace in the Zwift racing community.

In late 2018, ZADA was dissolved and there was an immediate fear that races would return to the “wild west” — with no oversight, racers could intentionally lower their in-game weight and use a favorable power sources without repercussions. While the community races didn’t exactly fill up with racers taking advantage of ZADA’s departure, it was clear that checks and balances were necessary to ease the minds of racers devoting so much time and energy into race podiums and leaderboards.

The Revolution

In December 2018, top-racers, Lionel Vujasin from Canyon ZCC and Matt Gardiner from Indoor Specialist, came together to envision a way for the community to voluntarily stand up in a show of transparency. Together, they developed a way for racers to support each other, hold each other accountable and to lift the veil on the data which is so important in determining the outcome of races.

Lionel and Matt created ZwifTransparency: a 100% voluntary and private (membership by approval only) Facebook group with the sole purpose of providing a place for racers to verify their in-game weight with live weigh-ins and to vouch for their power output with comparative data on multiple power sources and outdoor efforts / climbs. In the year since launching the group the membership has grown to over 1,000, members have voluntarily uploaded countless weigh-ins, and power meter dual analysis has become a community norm.

Weigh-Ins

On ZwifTransparency, racers weigh-in by starting a live video to prove their real-life weight. All videos are reviewed by a moderator before published in the group.

The protocol:

1. Weigh a marked weight (i.e 12kg dumbbell) on scale to verify scale accuracy

2. Step onto scale to weigh yourself

3. Hold marked weight and weigh yourself + the marked weight.

Since rider-weight in the game has such a dramatic impact on performance, racers weighing in are showing that the weight they have entered into the game is the same as their actual weight in real life. This simple process takes less than a minute, and is a massive display of transparency. Most importantly, this is 100% voluntary — a racer could do it one time and never again, or daily. Its completely up to the racer.

The norm established in the top-level races (such as the Zwift Invitational Pro-Am events) is to weigh in during the 24 hours leading up to the event. This ensures the racers are at their current in-real-life weight for the event.

Dual Analysis

Many top racers on Zwift race with the following setup: their bike with an on-bike power meter attached to a smart trainer. Since both the power meter and the smart trainer are capable of measuring and reporting power, the racer is able to record the power from both sources for any given ride or race. The recording of the two sources, and then comparing the files is Dual Analysis. It is the most effective method of determining whether a racer’s power meter is reading accurately and consistently.

Initially, Dual Analysis was a central purpose of the ZwifTransparency group. However, thanks to ZwiftPower’s development of a built-in Analysis function, racers regularly upload files for dual analysis directly to ZwiftPower for races to show that their efforts are legitimate and real. Exactly what ZwifTransparency strived for since the day it was started.

If you’re still scratching your head on what Dual Analysis is, Matt Gardiner has over 80 comparisons on his ZwiftPower profile, often comparing up to 3 power sources. To take a closer look, check out this file from one of the Tour de Zwift // Pro-Am Invitational races. Also, the screenshots below show two of the key graphs. The Power Output graph shows Matt’s output over the course of the race, while the Critical Power graph shows the power peaks (highest power for specific duration) for each power source separately — allowing users to see how the power meters compare at, for instance, 30s peak power, or 20 minutes.

The Future

As the number of users on Zwift grows and the sport progresses, the products important in eSports cycling (smart trainers and power meters) will undoubtedly be pushed to respond to user needs and expectations. The desire for consistency across devices in power accuracy and consistency has never been higher. For the Zwift racing community, racers will continue to take advantage of the ZwifTransparency group — weighing in periodically in a show of transparency and solidarity, and uploading dual recordings. However, a voluntary, non-authoritative group can only do so much for the community: racers are eager for a formal governing body.

As for ZADA, Zwift revived the initiative in the summer of 2019 in an official capacity for it’s Pro-Am racing circuit; verifying the top-3 racers from each race and testing 2 additional racers from the peloton at random. The return of the group is welcomed by the racing community, but only time will tell if we will see an expansion of this effort by Zwift eSports. For now, their is keeping the future plans for ZADA under wraps.

Whatever the future of Zwift racing: this is our community and together we will always strive for transparency and the fairest racing possible.