Virtual Doping and Clarity and What it All Means

I want to start out by saying I pretty much use Zwift as a training tool.  95% of my time is spent in workout mode.  I do races every now and then to supplement my training.  I’m about 186(84.54kg).  I have an FTP of about 295.  I race as a masters Cat 3/4 on the road.  I am by no means a dominate rider, but I can hold my own in most instances.   I have a quarq for use on the road and a hammer trainer for indoor use.   My normal setup is use a hammer (ANT+) with an (ANT+) HR strap.  I have a cadence sensor (ANT+) that broadcasts that to Zwift but the  Hammer is what controls Zwift.    NOW ONTO THE INTERESTING PART……

 This AM as I wanted to do the Tour of Watopia Stage Five but also complete my training for the day.  I hooked up a powered USB hub and thew on two ANT+ sticks.  I brought up my workout using PerfPro which is very similar to Trainer Road.  This for today will control the trainer.  I then set Zwift to read the Power from my Quarq.  Zwift still reads my cadence and HR but was not controlling the effort.  Here is where things get interesting……  I started the stage and my workout had a normal 20 min warmup.  So when the stage started I was shot out the back.   Well into the 190s in position.    As things progressed and my workout got into the meat (3X20 at 93% (275) 5 mins off (180))…  I was able to steadily make more and more progress.   This brought quite a bit of clarity to me as to the idea of Virtual Doping,  events, and races.  In the end I finished 107th out of about 400 riders.   When comparing the data files between Zwift, my Garmin, and the PerfPro they were all very similar and not statistically significant.

 What I came to realize is that removing the grade has a drastic and dramatic impact to the results.   It didn’t allow me to push more power or make me faster.  While keeping a continual watch on the riders I passed and passed me it became even more clear which ones I could more or less point out as having a setup which aided in better results.  You can call it virtual doping, or whatever you want.

 The take away from this is not to bash Zwift, other riders, or put any ill will on any person or the platform.    I did this only so I could complete my daily training workout while also completing the stage.  I am by no means a technical expert but I am savvy.  

 What I want people to realize is there are loopholes when we use all this technology.   Some people will figure out how to do this.  Some people may not even realize what they are doing.  Some may be lowering their weight.  Some may have mis-calibrated equipment.  Some may be doing all the above.   In the end Zwift is an awesome tool in my opinion.   For me it helps me pass the time not looking at a dot.   It’s a great motivator with the rideons and the gear upgrades.   There is a social aspect for those that want it.    

 In the end it’s a tool, and if you go in knowing it’s a tool to help you get better then whether you finish 1st or last you are getting better.  It doesn’t matter what that virtual rider is doing or if he/she is or isn’t being fully truthful.   Also please don’t turn this into what about events that offer prizes for position.  For starters I will never be a legitimate A top 10 and knowing what I know unless there are other safeguards in place I can’t see the end result being real legitimate.   CVR has checks and balances, but if people can compete in their basement being more or less anonymous with no repercussions then people will always find a way to cheat. 

 Maybe this will bring clarity for some, or upset some, or be that I told you so, but remember if you use it to get faster, fitter, lighter, or stronger then in the end Zwift achieved its purpose for you.

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Great perspective in light of all the recent drama about zwift cheaters and ftp braggarts, but I don’t really follow your experiment/conclusion.

“What I came to realize is that removing the grade has a drastic and dramatic impact to the results.”

Are you talking about removing the resistance from your smart trainer? (aka, non Erg Mode)

If so, how do you figure this is advantageous in Zwift racing? 

The other examples (weight or callibration) will clearly impact Virtual race performance, but I don’t see how trainer resistance would.


Interesting post. First, connecting to two platforms at the same time is kind of a cool idea–take advantage of the workouts from one while racking up XP and jerseys on the other! Haha. I like it. 

I’m trying to understand what you learned about loopholes and “virtual doping” using your setup. I assume by “taking away the grade,” you mean that your trainer wasn’t adding resistance (because you were in workout mode in PerfPro?). You said that this didn’t help you push more power or go any faster, but do you feel that this was the reason why you advanced from 190th to 107th place? Because another interpretation is that you started out in 190th, because you were in low wattage “warm up” phase of your workout, but then when you got into the higher wattage main set, you advanced 80+ positions. 

Here’s why I’m not following. I ride a dumb trainer with Garmin Vector 3 power meter, so no resistance change on hills. Taking away the grade certainly has some advantages, since you can maintain constant power output as the grade changes. But I find that when I hit hills, I struggle to keep up without spinning up to higher cadence or shifting to a higher gear to increase my power output, since many of those on resistance controlled trainers are cranking up the grade without shifting to a lower gear.

Also, at the end of the day, forward progress in Zwift is all about w/kg, and whether you’re resistance is controlled or not, you can still hit the same w/kg by shifting gears, right? 

Nick and Reinier…

I advanced because my power increased yes to ~3w/kg thats why I made up the positions.  But with the other tool controlling the resistance the grade becomes irrelevant.  I can continue to push ~3.2 watts steady keeping the same cadence and no residual effect of having the smart trainer clamp down when it hits 12-14% to slow me down briefly.    Anyone with just a power meter and “dumb” trainer will have this benefit.    I can push the same watts through any decrease in grade like in corners whereas someone with a smart trainer will have it release the resistance when it goes from 12% to 6% or when it goes from 3% to 12% the initial ramp will be irrelevant.  When you hit a portion where it goes from 3% to 12% someone on a smart trainer will all of a sudden jump to ~6w/kg  shift and then get back to ~3.  I was able to stay at ~3 and no additional muscle required.  Just like in a crit I can keep constant power or coast through a corner and the tail whip will require the last guy to get out and use more watts to catch up.  Then if you try to catch me you just had to push ~3+ watts.  Then you calm down to ~3 when you get to me but that continual physiological response need to stay will take its toll.  In a sprint you will be screwed in this instance as you would have to have something where you can up the resistant ahead of time but thats not a stretch.  esentailly someone with a smart trainer will require more work to keep up with me. 

“Anyone with just a power meter and “dumb” trainer will have this benefit.”

Having ridden that way on Zwift for a year before getting a direct-drive smart trainer a few months ago, I can say that I don’t see it as a benefit at all. Like Nick said, with no automatic increase in resistance on climbs (and the corresponding increase in power output it necessitates) - I struggled to keep up on climbs because the best I could do was guess as to which higher gear would approximate the effort needed on a given grade.  Sometimes I’d shift to too big a gear and blow up. Other times, too low and I’d spin and spin but not go as fast as I could/would IRL. 

I climb *significantly* faster on the smart trainer than I ever did on the ‘dumb’ fluid trainer, and it’s often the steeper gradients where I make up lots of time and pass people.

The downhill bit is something of a different story, and I can see how having your trainer fixed at 3 W/kg would be advantageous.

That said, the same ‘benefits’ can be achieved by running trainer difficulty at something less than 100% - but I prefer not to do that.

There are so many ways for people to cheat in Zwift races if they’re inclined to do so that you simply can’t take it too seriously. It’s not exactly news.





You’re not cheating - you’re just approximating the Shimano 11000 automatic stepless transmission.

I’ve done this myself i.e. doing a Trainerroad workout with TR controlling my trainer running on my tablet. I’m then doing a Zwift event on my PC. I overtake people during the interval sections then get passed during the recoveries.

I’ve also had several instances lately where I was doing a stage of the tour of Watopia and I took a screenshot. Not sure what happened but Zwift would pause longer than normal, then when I continued my smart trainer no longer changed resistance to match the grade. It then essentially became a dumb trainer and power was being picked up from my power meter. The effect in both cases was I  didn’t need to change gear and just rode more or less at a constant power with the occasional big effort. This was actually a nice way to ride and possibly less fatiguing. You can replicate this behaviour by changing the difficulty setting to zero %.

At the end of the day I don’t think this is virtual doping and if anyone wants to ride this way then good on 'em. Dumb trainer users of course, this is how they work anyway i.e. not changing resistance to match terrain.

BTW I run my Hammer trainer at 40% difficulty. I think many people who race don’t use 100%.

:)  I race at 100% TD, but it is all for me and it is only for fun. No Tron, no PU’s, just legs, lungs and liver.   :slight_smile:

Interesting thread. IMHO, riding without a high TD setting, one is just fooling themselves.

Well cheating is everywhere. In real world cycling on Zwift anywhere. To be honest it gets me thinking experiencing people cheating on a training platform just to boost their ego. I was doing Alpe du Zwift a few days ago at a pretty nice speed and i am in no means a newbie in cycling. Anyways, when you then see people doing 7w/kg and more the entire climb then there is nothing more to say. Seems like they missed their profession. Its also very interesting to see how thin and featherweighted 75% are on Zwift. People can’t even be true to themself. 

Cory - 300 watts at 100% trainer difficulty is just the same as 300 watts at 0% trainer difficulty.

Btw on my hammer smart trainer I find that 100% makes the same % climb as one outside harder ie it’s giving me a harder gradient than it should be. If I left it at 100% I wouldn’t make it up to the radio tower even though I can do the same gradient outside on the same bike. But hey, I’m just fooling myself.

The only thing TD sets is at which gearing you will use to ride. 300 watts is 300 watts and watts per kilo is what pace you will go up the climb. 3.6 w/kg is the same at 0 or 100 TD. But you will use a smaller rear cog on 0 and a larger rear cog on 100. It’s approx 2 to three shifts difference.

I am 5 foot eight and 88 kilo’s,considered small and chunky in the real world but I am a giant 75% of the time in zwift,cycling in zwift is like cycling through OZ with all the munchkins :slight_smile:

I clearly don’t take this game seriously enough!!  I jump on my Tacx Neo and choose a ride or workout and just get on with it…



“The only thing TD sets is at which gearing you will use to ride. 300 watts is 300 watts and watts per kilo is what pace you will go up the climb. 3.6 w/kg is the same at 0 or 100 TD. But you will use a smaller rear cog on 0 and a larger rear cog on 100. It’s approx 2 to three shifts difference.”

Power is power, w/kg = w/kg - this is true, and you won’t get any argument from me there.  I did the ‘dumb trainer + zPower’ thing for a long time before upgrading, so I know well enough what it’s like to climb in zwift w/ the equivalent of TD = 0. (It’s awful, IMO, but…)   

That said, it seems very unlikely to me that there are only ‘2 or 3 shifts’ (cogs) separating comparable efforts at TD=0 from TD=100.

If I’m grinding up a long 10% grade at TD = 100 on my Direto, I’m in my small ring (34t) and likely one of my largest cogs, averaging ~ 230W (@63 kg).  At TD = 0? The hills are “flat”. To make the same steady-state power on a flat road, I’m in the big ring (50t) and well down the cassette onto a smaller cog.

I fully understand that it’s all just, theoretically, a matter of ‘virtual gearing’ and math  and physics, and algorithms, and that the ‘total work’ for a given rider to climb any given climb is identical regardless of how said rider gets from the bottom to the top. (less power x more time) = (more power x less time)… I get it.

But the (vastly improved) realism of TD = 100 is everything to me. I want to use the full range of gears available to me. I want to train in a way that mimics the real world as closely as is practical.  Isn’t that why people buy $$$ ‘smart’ trainers in the first place?  If not, then what’s the point?