Pulse oximeter to track recovery

Some time ago I picked up a pulse oximeter to check blood O2 levels during workouts. That was a bust. :slight_smile: Started wearing it at night…just before going to sleep I like to do some Wim Hoff breathing exercises because those things work better than any other sleep aid I’ve ever tried…and maybe there is some third order benefit on the bike, who knows.

I notice some correlation between how my blood O2 & pulse vary during those breathing exercises & how proximal workouts go. I can feel fatigued but if it’s hard to move my blood O2 out of the 90’s I’m good to go. On the other hand I can feel OK but if the bottom drops out of my blood O2 & it easily drops into the 70’s or 60’s tomorrow’s workout is going to be a giant sufferfest.

Doesn’t work if you have had a drink. For whatever reason that keeps O2 up there no matter what.

Anyhow, maybe useful to some on the forum as a cheap & (maybe more important?) off-the-grid way to keep track of your recovery. Might also be that this interaction is unique to me.

My wife actually got one yesterday to be prepared in case one of us gets the plague. I was playing around with it for fun…kinda scared me as it would start beeping like I was going to die every time my heart rate dipped below 50bpm.

Yeah! For 20 bones it’s worth having just to screw around with. It’s interesting that low or high blood O2 didn’t really jibe with any sort of feeling I had. Feel like you’re suffocating during a VO2max interval? 95%+ On the other hand 78% (or lower) can feel quite comfortable during Hoff breathing cycles.

Most home medical devices aren’t well calibrated for athletes, especially those that track HR and have an Irregular Heartbeat Detection feature. I regularly set off the IHD on our blood pressure monitors because my low HR trips our algorithm for arrhythmia.

I think it might be useful in case you get quarantined at home to detect silent hypoxemia, but make sure you are aware of pittfals of wrong readings as well as not getting too obsessed with it. guess it’s practical to detect a trend.

hard to believe SaO2 drops to 60s or 70s, considering the oxygen–hemoglobin dissociation curve, where O2 saturation drops exponential from ~ PaO2 of 60mmHG

bought one myself recently out of curiosity and it was pretty much spot on compared to a 25k$ medical device

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this might be due to your circulation centralizing resulting in low blood perfusion of your extremities ?

You know what, Fenton? That is an elegant hypothesis the more I think about it…

For sure, if you do it correctly, you’ll feel your nasal passages dilate. So something is going on.

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Ha! Give it a try! 70’s are a lead pipe cinch. After a hard week of training you’ll touch the 60’s. Or maybe it’s just me kidding myself with a janky pulse oximeter, a wild imagination, and too much time on my hands.

so you are saying your pulse oxi reads 70% O2 saturation while you are resting after a week of hard efforts?

I assume the latter is the case :slight_smile: but more than happy to be proven wrong

If it was reading 70’s for any length of time you might not be alive. Sure you don’t have obstructive sleep apnea? Are you snoring when this happens? There are many reasons why pulse oximetry might not be accurate. I work out quite a bit and have never had an oximetry reading in the 70s.

just before going to sleep I like to do some Wim Hoff breathing exercises because those things work better than any other sleep aid I’ve ever tried. During those breathing exercises blood O2 can get below 70%. Try it. You’ll see.

When I’m really fatigued and I do the breathing correctly the bottom can really fall out & O2 will drop into the 60’s.

I bet that’s true! :smiley:

Nope. Fully conscious. Just using some breathing techniques. I guess I thought these exercises were more well known than they might be.

But you are correct…O2 doesn’t stay that low for long. The goal of the whole process for me isn’t to get blood oxygen down as low as it can go. That’s just an observation I made while screwing around with the pulse oximeter .

The interesting thing…whenever blood O2 gets real, real low during the breathing exercises the next day’s workouts are usually a real struggle.

But if the novelty of low blood O2 interests you pick up a pulse oximeter, follow the breathing protocol, and you’ll see some pretty low numbers I bet!

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I’ll try (while not killing my remaining brain cells)

holding my breath will bring me into the upper 80s range, where I already feel my body’s fighting it (although the breathing reflex is coupled to CO2 build up and not Oxygen in healthy people)

suffocating then? :wink:

just sitting on the couch resting I’m at 96% I’m still at 93% after holding my breath for a minute. Pretty sure if you’re measuring 70% your sensor is not very accurate as you’d be losing consciousness


Those finger things measure oxygen saturation in your finger. If you were to be able to measure oxygen saturation in the blood leaving your lungs I bet it’d be near 100%.

I actually have one for going up mountains and it has been in the 60s. Feels fine till you try and sprint between tents. Even slow walking uphill was fine and dandy.

I don’t think it’s the low oxygen saturation in your finger per say that makes you feel bad, but how you got there. If you exercise near sea level and are exercising so hard it has restricted blood flow to your arms that much then I’d expect to feel pretty bad.

I’ve never actually tried during exercise because of having shoes over my toes and not having considered fingers. Even toes I was sceptical about because they aren’t exactly very active, but I’ll have a bash tomorrow and see how low it gets for a laugh. I have one of those automated blood pressure cuffs too. I wonder whether the number will be bigger or smaller…

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That’s not true. Mine has been upper 60s when I’ve been at altitude. It’s quite normal to have lower numbers at altitude. Furthermore this is a peripheral finger measurement, not a central measurement, in someone who is probably so relaxed their heart output is reduced and that reduced output is being preferentially sent to a relaxed brain, rather than an inactive finger. If the blood leaving their lungs had Oxygen levels in the 70s at or near sea level that would be bad, but we don’t know what their central oxygen saturation was or what altitude they live at.

I’m a bit confused…what kind of breathing exercises cause oxygen levels to drastically drop? Do these involve a plastic bag or saran wrap or something??

‘Just holding your breath’ isn’t what I’m doing. So that’s probably the difference! :wink:

I’m not sure how it will go if I just hold my breath. Lemme try here while my tea is steeping…Ok. I held my breath for a minute & my blood oxygen reading dropped from 96 to 94. So, I agree with you…just holding your breath might be an interesting diversion but it’s probably not going to drive your blood oxygen down.

Lemme see what blood O2 does after one round of Wim Hoff. I just got off the trainer…not sure how this will go. Cross your fingers…ok, started at 97 & finished at 84. Apparently technique does matter! :smiley: Certainly if the exercise were completed blood O2 would dip well into the 70s.

Tonight I’m going to dilate the capillaries in my skin & test fenton’s (most likely correct) hypothesis.

Just a quick follow up…after doing this for a little bit & tracking the results through the highs & lows of a TR plan. This works WAY better than any HR variability recovery advisor I’ve ever used. FirstBeat analysis often leaves me scratching my head. Garmin Recovery Advisor works primarily by keeping you in a perpetually ‘fresh’ training state by flashing super long recovery times after workouts. I’ve used a couple other pay services…

For sure, if I’m fresh I have trouble getting my blood o2 out of the 90’s. When I’m flogged blood o2 will drop into the 50’s.

So maybe it’s a little like the old PalmPilot approach where rather than trying to recognize everybody’s handwriting they taught everybody to write in a new way. Instead of trying to measure recovery using everybody’s breathing/heartbeat just teach everybody to breath a certain way & watch blood o2.

As mentioned, alcohol screws it up. Also, I took 1.5 grams of niacin & tried the method once. Niacin screws it up, too. Big time. Also, the whites of my eyes turned red for about 20 minutes.

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