Wahoo Kickr Core & Air Pollution Around Bike

Hi All!

I know this is an idiosyncratic question, but I have a concern about the air quality around the Kickr Core. I have have been using one 6 days a week for zone 2 and VO2 max HIIT since July 2021. I also have mild asthma.

I also bought an Air Quality Egg which is used at universities and some governments to measure pollution, including PM2.5, NO2 from cars, and PM10.

After half an hour on the Kickr Core, the measurements for NO2 jump from about 23 pp/b to upwards of 50-100 pp/b.

PM2.5 jumps from zero or 1 to 20-30 units, the higher end of safe levels.

This is colourless and odourless. You would never know without the air measurement device.

Has anyone else ever tested air quality in the room where the Kickr is used?

I’m not looking for simple advice around ventilation; rather, whether anyone else has evidence of a concern with stationary bike or direct drive devices. Would be interesting to compare notes.

Also would like to raise awareness for anyone concerned about their air quality.

It’s not great that you can work so hard to be fit, only to potentially harm yourself from something out of the blue like this. This is the problem of air quality that we never think about.



I am no chemist, but I know NO2 is a (obv bad) byproduct of fossil fuel emissions. Can’t imagine how a stationary trainer using magnetic impedance resistance would be off-gassing NO2.

Are you thinking it’s coming off the device from the manufacturing process?

Not familiar with your detector, but is it possible it’s picking up nitric oxide (NO) production that you are excreting from exertion? Because that’s very much a thing, and would lend itself to the idea of an NO “cloud” collecting around your training area (and you) during your training effort.

As you are an asthmatic, I could even see your body pushing out increased concentrations of NO and other byproducts due to the reduced efficiency of oxygen intake and absorption.


No, my asthma has nothing to do with reduced efficiency. It doesn’t work that way. My lungs are far more efficient than most people’s lungs, for a variety of reasons. My minimum lactate zone 2 is 200 watts and goes up from there.

Never hard of NO production getting into the atmosphere. That may well explain the issue! Do you know of any online articles or sources on the topic of body produced NO getting into the atmosphere during exercise?

I didn’t see the article at first. Still it would be interesting to see how this shows up in the air not only the blood.

Metabolism of NO. First diagram in this link, our body breaks it down into NOx, then gets rid of it in various ways, including breathing it out. Have no idea if the quantities are high enough to be measurable.

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Interesting and something worth investigating. Could be a lot of things going on. First thing would be to check the detailed specs of the sensors used in the device and the specs of the device itself. What do they detect, how specific are they, accuracy, etc…

Particulates could come from a lot of things, like clothing that’s moving/abrading as you exercise or even dander being shed. Probably get something from shoes on the pedals and maybe even the drivetrain. I imagine the belt in the Kickr could generate some, and certainly the tire on the roller of a wheel-on trainer.

I’m never riding the trainer without a good breeze from a fan, which would certainly affect air quality in some way +/-.

Welcome to the forums @Canadian-Ice. Interesting topic. Thanks for posting!

FYI, I moved the topic to the Equipment category.

Thanks guys.

That’s a really good question, whether the amount of NO2 from breathing or perspiration would be enough. It is clear from the diagram that some NO2 leaves the lungs during exercise. I do know that humidity increases from below 50% to well over 70% as shown by the air quality sensor during exercise, so no doubt water vapour from perspiration is significant.

Yes the belt and drivetrain could definitely be generating some particles, so the increase in PM2.5 is not surprising. It does seem odd that significant NO2 would be created.

I did contact the Air Quality Egg people and the one engineer I spoke with gave the disinterested opinion that anything that generates heat could produce NO2 increase. Not sure what that’s worth. I am not certain that the AQE is accurate.

It is worth contacting the Wahoo people about this. I wounder if they ever tested the atmosphere around their trainers thoroughly? Unfortunately they probably won’t release their results if they did.

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Do you use a fan with a brushed motor while using your Kickr? These do produce ozone and could be the cause of a false reading?

Whatever the cause I’d just open a window, I ride in my garage and keep the door ajar. If your Egg measure co2 levels can it detect an increase if you ride with the doors and windows shut?

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No, I use an Austin air filter which blows like a fan while cleaning the air of most particles but not a lot of the gasses. I live on a relatively busy road so workout with the window open about 6am, like now, when there isn’t a lot of traffic yet.

It doesn’t make a lot of sense to me that a direct drive would cause as much pollution as a lot of cars, which is exactly what this Air Quality Egg is showing. But if anyone know of any other research on the topic please let me know.

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Agreed, this makes no sense.

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Is it possible that outdoor air quality degrades over the course of your workout as traffic builds and the sun comes out? I notice you keep a window open.

If you’re measuring the difference between when you start your workout and during, in a morning, having had the windows closed but now opened for ventilation while you workout, have you tried simply opening the windows at about the same time in the morning, and using a secondary source (you flapping a towel) or similar to create new circulation of air in the room introducing air from outside to see if it is purely an environmental effect?
Essentially, have you done a control test to see that the core factor isn’t simply opening the window and allowing the air to come inside?


When the air was tested, the window was closed for the workout. Only materials from the direct drive (and myself) were measured. The baseline was the same room prior to the workout. There’s nothing that could be measured other than myself and the bike.