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Is there an easy way to measure aerobic threshold?

marcjf

Senior Member
Messages
127
Ok, here is my issue.

Like many of you, I have exertional intolerance. Mine is usually presented not as fatigue though, but as pain. I can go swimming for a little bit and be fine. However, I can extrapolate on intensity and experience post-exertional pain, tingling, petechiae, etc. That will take a little bit to recover from. It seems to affect mostly my legs, but I would not say symptoms are limited to that.

I think I have peripheral issues with the oxygen delivery, no sign of pulmonary or heart issue. Also, that seems to be the common theme among Covid long haulers: https://journal.chestnet.org/article/S0012-3692(21)03635-7/fulltext

I read all about Dr. Systrom and the iCPET. I think that should have been the gold standard for exercise intolerance, but unfortunately it isn't, so it is not something it is widely available outside his practice. I also do not have $20k+ laying around to travel abroad to US and get it soon (and they are also probably pretty backed up anyway).

I could probably get a regular CPET locally, if I wait. Then check the lactate levels, which should help to some extent.

But I would like something that would help me on a day-to-day basis, and could somehow objectively help me measure it, and also experiment with certain compounds. I want to know if Mestinon, Midrodine, etc. could increase that limit without risking further damage. When I happen to cross it, it is usually already too late. I do get some signs though.

There is a sensor called Moxy (https://www.moxymonitor.com/) that seems to try to do that, but I haven't heard of any reviews from the ME/CFS community. It tries to measure the SmO2, which is a metric used to measure oxygen delivery to the muscles. It is supposed to check if you are crossing the lactate threshold without having to go to a lab for that. I believe it is targeted for athletes that are trying to pace during endurance competitions.

I have no idea how reliable it is though. It seems pricey, but honestly, if it actually works, it is cheaper than the alternative, given that you can keep reusing it.
 

Martin aka paused||M.E.

Senior Member
Messages
2,291
It is supposed to check if you are crossing the lactate threshold without having to go to a lab for that.
That's very interesting! If it comes with an app that could alarm you (bc on the website they say it does real-time measurements) that would be sth that could be useful as a PEM warning device.
It's quite expensive though. So one had to be sure that this is really helpful.
 

marcjf

Senior Member
Messages
127
That's very interesting! If it comes with an app that could alarm you (bc on the website they say it does real-time measurements) that would be sth that could be useful as a PEM warning device.
It's quite expensive though. So one had to be sure that this is really helpful.

Yes, I want to make sure of that before making such a big investment. I could find 0 reviews coming from Long Covid/ME communities though. It seems to be a very niche product, so I guess that is expected. I found a more thorough review from an athlete's blog: https://fellrnr.com/wiki/Moxy
They also do a good job explaining the difference between using Sm02 and blood lactate: https://fellrnr.com/wiki/Muscle_Oxygen_Saturation

It is definitely not a trivial device for someone to get started. So one would have to invest money and TIME on it.
And I think we still need more research papers to back up its accuracy. Some recent papers shed a positive light though: https://www.spiedigitallibrary.org/...ration-on-a-0/10.1117/1.JBO.24.11.115001.full


If you page down this article linked below, under the section titled, "Hannah's Approach" they give a way to do an estimated anaerobic threshold. I'm not sure if that's exactly what you meant.

https://www.healthrising.org/blog/2...art-rate-monitoring-chronic-fatigue-syndrome/

Anyway, hope it's somehow helpful to you.

Thanks for the suggestion, Judee. I bumped into this strategy a while ago. I used to actually monitor my HRV through a very nice app called EliteHRV(https://elitehrv.com/). This one is free, and works with several heart rate monitors. I highly recommend it for anyone that wants to keep track of it.

I think there is some validity in using the HRV, but it is a bit disconnected as a metric. I believe there is more interplay between HRV and other factors as well.
For example, I found really easy to boost my HRV simply by doing diaphragm breathing while measuring. But we know we cannot fight PEM with breathing.
I also think there are some other limitations to its usage.