I’ve been collecting CO2 data during indoor training and doing some informal analysis the results are quite stark. Staying below 600 ppm is definitely best and how far below doesn’t seem to matter. 600-700 sees slight performance degradation. Above 700 is consistently measurable degradation and above 1400 seems a consistent 30% lower performance.
How difficult would it be to add this in as a metric? I’m currently doing either 1 reading per minute or 1 reading every 6 seconds.
Interested if others have been tracking this as well and what you’re seeing.
Yes. CO2 is measured in PPM and is an integer typically between 340 (lowest level typically recorded outside) and 9,999. I get a measurement every 1 minute (uRAD A3 monitor). It will typically be about 420 at the start of an indoor workout and then rise from there. If I have a window open and air flowing out of it then CO2 will rarely go above 800 and my performance will be high. If I’m not getting good airflow then CO2 can go as high as 4,000 ppm.
I’m seeming to notice performance impacts at about 1,100 ppm and significant impacts at 1,800.
@Quincy_Five You’ve nudged my interest. Somehow I hone in on these topics.
Is this CO2 build-up a part of the ambient air pollution where you live or just internal to the house due to poor ventilation? My first inclination would be to ask how are you sampling the air?
420ppm sounds ok (I mean its really not okay but CO2 at Mauna Loa averaged 417.14 ppm in March!). 4000 ppm is an order in magnitude higher. Last time I looked, the ASHRAE interior air standards called for CO2 to be kept < 700ppm. That aligns with your observation around the 600-700 mark.
Curious what is the performance degradation? Higher RPE? Headaches? Nausea?
@Coach_Ron, this is CO2 accumulation in the room where my TACX bike is set up. I’d originally planned to have my TACX in our gym which has a 300 CFM exhaust system to keep CO2 levels (and odors) low. If I’d known it’d be in this room in our loft I’d have installed an exhaust fan in there (which I may do yet). When I can I’ll open the window in there which results in natural exhausting, lower CO2 and better performance but when it’s raining, snowing or really cold out then that’s not a good option.
420 PPM is actually pretty good as a base indoor ambient level. Fewer than 1% of homes in the U.S. will have anything much lower than 440 with many above 800-1200. Our outside level is around 390 PPM and we have a quite extensive ventilation system that ventilates 10 minutes / hr as well as anytime CO2 levels are above 550. We have just about twice the ventilation recommended by ASHRAE and I’d say we barely have enough.
Normal sampling is done w/ a uRAD A3 which is one of the most accurate available for the $. We also have 4 IQ Air monitors, an AWAIR v2 (v1 were terribly inaccurate, v2 much better) a Foobot (the most inaccurate available) and a couple of others in addition to the 7 sensors for the ventilation system. I have a Gaslab 505 that’s used when greater accuracy is needed.
Performance degradation is largely fewer watts produced. Occasional headaches but only over about 1800 PPM. When I get time I’m hoping to do a lot more CO2 analysis including heart rate, Blood Ox, Lactic acid (if we can get a working K’watch or something), etc.
