I was having a conversation with my dad about O2 levels the other day…
Anyway…the end result of it was I did some testing to see if riding would affect the O2 reading.
So, I did a VO2 max workout. It was one of the ~5 min intervals that alternates between 88% and 125%.
End result - I consistently had a reading of 98% during the 40% rest periods. It would tick down to 97% about 30 sec into the interval, then go back to 98% during the recovery. This was tested the forst interval, and the last interval at the 1 hr mark. No change.
91 to 94 percent indicate mild hypoxia (loss of oxygen)
86 to 90 percent indicate moderate hypoxia
Anything under 85 percent indicates severe hypoxia requiring immediate medical attention
If you notice consistent levels from 86 to 90 percent, you may need to see a doctor, or your meter may not be measuring accurately. Test it on a few other subjects to see if the meter measures their oxygen levels as low, as well, to determine whether you need to seek medical attention, or you’re just experiencing technical difficulties.
How the Numbers Change
When arterial numbers are normal, usually about 95 to 100 percent, you’re breathing in and using plenty of oxygen. These numbers generally stay unchanged during moderate intensity exercise and may even increase a little with the intensity, suggesting you’re breathing faster and therefore taking in more oxygen. With more vigorous exercise, you may note a small drop in blood oxygen levels of about two to three percent if your respiration doesn’t continue to bring in enough oxygen to meet your body’s current needs. In this case, you may notice levels as low as 92 percent. However, when you stop exercising, these levels will return to your normal reading. The better shape you are in, the more quickly you will see these levels return to normal range.
Looks like you understand the concepts pretty well save the breathing technique.
google Rd9XfQLY5rQ or 6A4t97S4mRQ or OEwoB7j-uQw there are probably a dozen other videos…
I thought this technique was kinda trendy but maybe it’s not as well known as I thought. It is kind of from a decade ago so maybe it’s come and gone. Anyhow, I don’t want to go on & on about it…I’m not an advocate except to say it’s a great help to get to sleep & it can provide some insight into your state of recovery (says I).
I’d really worry if I wasn’t doing some sort of altitude training and saw numbers below 90% at any given point. Here is my chart for 1 month coming from sleep and my Garmin 5X Plus.
Ermagah. There really is a deficit of understanding, here. I guess there’s nobody to blame but me, though! See the first paragraph of my post titled ‘Pulse oximerter to track recovery’. Second sentence. Right after the ellipses.
Yeah, that’s what I thought! This is a trendy thing that’s been around for a decade. I don’t want this to be a thread about Wim Hoff. I’m not an advocate of his ideas & you may notice that I give him an ‘f’. That’s for hyperbole. Somebody once told me, ‘Hey, I started doing this breathing and it improved my performance 15%.’ I thought that sounded like BS, but, hey, y’know somebody once told me they huffed xenon and it improved their performance a lot…that turned out to be true & it was a lot more difficult to verify than goofy Wim Hoff breathing. So you never know. Anyhow, Wim Hoff breathing doesn’t improve your performance but it is a great way to get to sleep.
I’m not sure how you would drown from doing it but I’m not steeped in the ways of Wim Hoff.
Holding your breath for prolonged periods of time causes your blood O2 to drop, which can cause you to pass out. There have been reports of people doing this whilst in water where the passing out caused them to drown.
CO2 levels regulate your breathing reflex (in healthy individuals, some COPD patients it’s O2), so due to hyperventilation you become hypocapnic leading you to be under water w/o feeling the need to breathe, then you’re more likely to pass out because lack of Oxygen, which will then probably result in drowning when no one notices …this can also happen playing around in your bathtub e.g.
So I didn’t believe this but gave it a shot and spO2 dropped to 85 the first time I tried it. Last night after a TT in the daytime and plenty of wine at night it dropped to 74. I’ve done it exactly twice, mainly because 30 breaths takes a surprisingly long time!
It is strange emptying your lungs and then not breathing and not really feeling like you need to breathe. It takes me ~90 seconds to feel like breathing again. I’m not struggling or uncomfortable in any way while not breathing, just sorta sitting there looking at the pulse ox number.
This has got to be because the hyperventilation causes hypocapnia/low CO2 as Fenton said, right? So your O2 levels drop but you don’t feel the need to breathe? But you can see it happening with the pulse oximeter? Is this pulsing hyper/hypo ventilations supposed to be a good thing?
Finally…are you saying if the number drops a lot then you feel you aren’t fully recovered? And if the number doesn’t drop much then you are more recovered? I’d love to find a decent way of monitoring recovery, heart rate variability didn’t seem to make any sense for me at all.
When I’m feeling smashed after a hard week of training & my blood O2 drops into the 50’s pretty easily…probably tomorrow’s workout is going to be a real problem. If I’m feeling smashed and blood O2 holds low 70’s/upper 60’s…good to go.
But by now I’ve got myself so convinced that it could just be a mental thing.
Recently seeing a new doctor (chiropractic neurologist) who is checking my SpO2 levels each visit via a pulse oximeter. He seems to think it’s low (96) considering my fitness/activities. This is a new metric for me. Is 96% low for a cyclist?
96 is indeed low-isch. I get mine checked in the hospital every 3 months due to underlying health issues and the doctor is generally satisfied when seeing 97-99%.
Pro-tip: make sure you’re breathing deep n steady when performing the test. Some people, like me, tend to breath very shallow/irregular causing a slightly lower reading. As soon as the doctor gave me that tip I could see the saturation rise 1-2%.
I’m chronically in that range. I just try not to let it bother me. My lungs have collapsed half a dozen times and been punctured once so I’m sure there is some damage in there. Meh. What are ya gonna do?
And established a baseline of SpO2 readings first thing in the morning. Mine were mostly 98-99% range. My sister-in-law recently had COVID and she used it, her levels were around 92% while sick.
There are other reasonably priced pulse oximeters on Amazon.
There really is a deficit of understanding, here. I guess there’s nobody to blame but me, though! 
See the first paragraph of my post titled ‘Pulse oximerter to track recovery’. 
Second sentence. Right after the ellipses.