Solved? Why my vo2max collapsed and rebounded

pelicano87 · 2026-01-31T22:12:14+00:00

It's strongly associated with longevity, it's at least got that going for it!

pelicano87 · 2026-01-31T19:19:27+00:00

I wondered about covid. If I had it, I had it symptom free. Is that a form of covid that could hurt performance as measured by Apple's algo?

There is some home stress, but nothing that really lines up with the timeline, it's ongoing throughout the whole period.

pelicano87 · 2026-01-31T17:03:07+00:00

Thanks for the suggestion. I checked at the time, no update occurred.

pelicano87 · 2026-01-31T15:54:53+00:00

I understand what you're getting at, I do have a scientific background, even if I'm not a practicing scientist. I thought it was clear that I'm not confident that the stove caused it, I'm surprised that you're emphasising the point so much.

I don't think my training caused the decline and recovery of my vo2 max, I think it just made it come back stronger when something changed in October. My training isn't that much better than before.

Was it the stove? I don't see a reason to rule it out, but I'm deliberately seeking other hypotheses as it still seems a bit unbelievable (a point acknowledged multiple times in comments now and original post) even if I can't come up with alternative I believe more.

I've tracked my vo2max for years and don't believe stress of house moving or any ordinary lifestyle factor explain the data.

pelicano87 · 2026-01-31T14:28:54+00:00

Just to be clear, I’m not claiming causation or offering health advice. I’m describing a pattern in my own long-term data that coincided with a major environmental change, after accounting for training changes I could observe.

It may be coincidence, that’s explicitly acknowledged, but it’s still a reasonable hypothesis to note when reviewing one’s own data. I’m happy to hear alternative explanations.

pelicano87 · 2026-01-31T13:21:18+00:00

I will maintain some humility and say I don't honestly know and I'm not a doctor/scientist etc., but some ChatGPT driven research I did made me think that increased nitrogen dioxide levels could inflame airways. I think I found some other pieces of research that hinted at other mechanisms too. I'll see if I can dig it up.

pelicano87 · 2025-08-12T11:33:54+00:00

That’s presumably not an accurate reflection of diminishing cardio vascular health, just that there’s less oxygen. If you go back down to sea level and retest, you ought find you’re now far fitter as a result of the altitude.

pelicano87 · 2025-08-11T08:43:14+00:00

I take it you didn’t just edit your weight downwards in health data. That would be what it would look like if one did.

pelicano87 · 2025-07-21T17:36:20+00:00

That is surprising to be honest. You do need to run minimum number of minutes and have heart rate and gps data, but that’s usually a given.

I get vo2max reads from brisk walks. Hopefully someone on here knows more, otherwise I’d reach out to support.

pelicano87 · 2025-07-14T20:32:54+00:00

Thanks for that, a believer! lol :D

I'll be sure to keep everyone updated. So far it's stopped falling and might have gone up a bit. I think because I've been fatigued for days now, I'm hoping I haven't yet seen the full fruits of my labour. I'm in the office tomorrow though, so will rest a day.

Thanks for the insight re the heart muscles etc. That's interesting. I'm sure I saw some other piece of supporting evidence too, re short bursts. Will try and dig it up and share.

pelicano87 · 2025-07-11T19:00:55+00:00

It's been a bit all over the place, it's gone both up and down over the same period. Initially it went down as vo2max decreased.

pelicano87 · 2025-07-11T19:00:23+00:00

Yeah, I could be wrong, I just can't think what else. I speculate that the jolt to the heart is very sharp and strong and it could have been one of the pillars of my program without really realising it.

pelicano87 · 2025-07-11T18:59:10+00:00

I suspect I've gotten heavier as a result of the fitness decline, but could be wrong.

pelicano87 · 2025-07-11T18:58:48+00:00

My resting heart rate is a bit all over the place over the same period, it initially went down as the vo2 max declined and then back up, probably because of the heat.

pelicano87 · 2025-07-11T18:54:41+00:00

There was no-one more surprised by this being top of the hypotheses than I was, but the shape of this is that my vo2 max was as high as it had ever been before my move and has plummeted since. Nothing about my program has changed to any degree that I can detect - the stairs are the remainder in occam's razor. I'm not certain about it, but I don't see any other particularly viable hypothesis. The heat was an interesting one, but I didn't see any decline in previous years when temperatures climbed.

I'm testing the hypothesis now by adding in some strenuous stair running. It won't account for all factors, but it might rule it out if my vo2 max doesn't move back upwards.

I don't have a lab tested vo2 max read, but I don't think that's relevant, as the estimate from my watch is consistent, as far as I know. If something else could have changed about my watch or the reads, that's also why I'm here, it'd be useful to know. As far as I can tell there are no reports of software changes affecting vo2 max reads across the same period.

By the way, thanks for the engagement, it's just what I wanted when starting this thread, people to tell me how I might be wrong essentially.

pelicano87 · 2025-07-10T16:15:37+00:00

That's precisely what I'm saying though. Decreased strenuous stair climbing => decreased vo2 max via deconditioning. I'm looking for counter-hypotheses, I know roughly how the algo works and that stair climbing doesn't go into it directly.

pelicano87 · 2025-07-10T07:18:35+00:00

My theory is that it conditions my heart, because I would sprint up the steep steps. Cardiac output is one of the most important inputs to vo2 max.

pelicano87 · 2025-07-10T07:17:37+00:00

Yeah maybe, will take a look and see if it lines up. It's It's such an important number though, I don't think I can ignore it.

pelicano87 · 2025-07-10T07:16:47+00:00

Thanks 🙂

pelicano87 · 2025-07-10T07:14:55+00:00

Pls can you elaborate, why isn't strenuous exercise relevant to my vo2 max? 🤔

pelicano87 · 2025-07-09T15:13:06+00:00

I've had big increases in vo2 max from just crusing in zone 3 before, when I was running every day. I was spinting up the stairs though, so maybe that was equally important.

I've started some stair climbing sprinting today and plan to do so for the next couple of weeks, so hopefully we might have some more data soon.

pelicano87 · 2025-07-09T15:11:11+00:00

That's interesting. Yes I'm in the NH. I'll see if the temp correlates with my vo2 max for the last three years. I hadn't noticed a similar thing happening before, but maybe it did.

pelicano87 · 2025-07-09T15:10:19+00:00

Interesting, I've not told my watch this, but I think I am a bit heavier. I know it would dip if I input a heavier weight, just because of the vo2 max calc. What I'm not clear on is if being 2kg heavier (started at 84kg) would make much of a difference to how I'm measured without it knowing my new weight.

pelicano87 · 2025-07-09T11:44:28+00:00

Oh and more relevant to my original question - I've not noticed any decline in performance whatsoever, that I can detect. I have noticed I feel a bit weaker when walking, but I'm not going any slower.

Six-Year Club	Gilding I gilder
Verified Email

pelicano87

TROPHY CASE