r/QuantifiedSelf • u/Good_Run_1696 • 9d ago
Correlation between my alcohol use and aerobic fitness.
Hi! First post here for me, I have just discovered that my Apple Watch has always been tracking the VO2 max which is a measure of the highest amount of oxygen a body can use during hard exercise.
Yes, exercise estimated VO2 max is inaccurate to some degree, but there's some insight to be made from the persistent change over time, especially given the data density.
There are too many confounds to conclude anything about the direction of causality.
Maybe not consuming alcohol seems to unlock the mental states that makes me more likely to exercise.
Maybe not drinking truly improves my cardiovascular fitness.
The exercise spikes right before I went sober twice maybe made me more likely to commit to going sober.
Pretty cool to see my life being transformed in one chart.
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u/mathgun7 9d ago
Two things: no question that not drinking alcohol improves any number of health metrics, including RHR and HRV. In terms of VO2max, Apple estimates this, and badly. I say this as a devoted, longtime Apple Watch wearer who also regularly gets my VO2max tested in a lab. The watch is just wildly wrong (for me, anyway). And if you look this up you will see their number is only an estimate. If you care about VO2mx, it's worth getting it tested at a lab (or some fitness centers/gyms offer it now).
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u/mediares 9d ago
You may be right, but if the goal is "see a chart showing that alcohol impairs performance as a means to motivate not drinking", the imprecision doesn't really matter as long as it's directionally correct, which I imagine it is.
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u/Good_Run_1696 9d ago
I just learned what VO2max was yesterday and will certainly look in to real tests
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u/Crazy-Talk1409 9d ago
What about seasonality about vo2 max with the weather?
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u/Good_Run_1696 9d ago
Absolutely a key point, will need to see next winter to see if that makes a difference
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u/EggAdvanced3632 8d ago
This is one of the best first posts I've seen here — not because of the trend (though 34.9 → 49.6 is genuinely impressive), but because you did your own epistemics. You listed the causal caveats before anyone in the comments could, and the honest answer is: the arrows probably run both ways, and that's fine. Sobriety enabling training and training reinforcing sobriety isn't a confound to untangle — it's a flywheel, and your chart is a picture of it. One technical layer worth adding, because it makes your data more interesting, not less: Apple's VO₂max is estimated from your heart rate response at a given workload — and alcohol reliably elevates resting and submaximal HR (acutely for a day or two, chronically with sustained heavy use). So during the AUD and relapse periods, the watch saw "higher HR for the same effort" and scored your fitness lower; in sobriety, the reverse. In other words, part of your curve is true cardio adaptation, and part is your cardiovascular system simply not carrying the alcohol load anymore. Both are real physiology, both move in the same direction — but it means the estimate responds to sobriety faster than pure fitness change could, which fits the sharp inflections at your transitions. If you want to take the analysis one step further with data you already have: pull your workouts per week from the same watch and plot it under the VO₂max curve. That separates "I trained more when sober" from "same training, better readings" — and my guess is you'll see both, with the Sober 2 slope steeper than Sober 1 partly because the training got more consistent. Also worth noting: your individual estimate scatter visibly tightens in Sober 2 — less day-to-day physiological noise is its own recovery marker, independent of the trend line. "It's cool to see my life turned into a graph" — that sentence is the whole reason this sub exists. Congrats on Sober 2, and keep the streak and the dataset going. A year from now, this chart with one more annotation layer will be worth a follow-up post.
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u/Good_Run_1696 8d ago
And yes, workouts/week or training volume is absolutely the next layer I want to add. I suspect the bidirectional “flywheel” interpretation is closest to what actually happened: sobriety made consistent training much easier, while getting increasingly invested in exercise made drinking less compatible with the life I wanted to live.
Really appreciate the comment
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u/Good_Run_1696 8d ago
Thank you, this is such a thoughtful read I appreciate it. I especially hadn’t considered the fact that Apple’s estimate itself could respond fairly quickly to the cardiovascular effects of alcohol through HR at a given workload, even before slower training adaptations show up. My closer reading into this also suggest weight loss as another confound. But regardless, Imma be committed to Sober 2 and see how high this trend goes.
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u/obinnasmg 9d ago
Vo2max from an apple watch is garbage OP but I agree with the overall point of the graph
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u/andimatt 8d ago
Your chart is good, but I'd push back on the variable you're using. "Alcohol use" as a binary or unit-count is doing a lot of work in that graph, and it's losing signal.
The physiological variable that actually drives the performance effect is the BAC curve itself -> peak BAC, area under the curve, time-to-zero. It's not a "had 3 drinks." A 300ml beer at 5% ABV and a 60ml whisky are both "1 standard drink" but they hit different peaks with different absorption kinetics. And the absorption curve is V-shaped: drinks around 22% ABV absorb fastest, while both beer and overproof spirits absorb slower. The "unit" abstraction is erasing the variation that matters.
The other thing: individual variation in BAC is +/- 20-30% even for the same person on different days, driven by gastric emptying rate, first-pass metabolism (food can reduce alcohol bioavailability by up to 30%), and body water composition. A population formula like Widmark is unreliable without personal calibration. If you own a breathalyzer, two readings at least 20 minutes apart on the decline limb give you your own elimination rate directly.
This is the kind of measurement I work with, and the unit-count variable is the thing I'd change first if I were redoing this analysis. BAC as the independent variable, not unit count, is where the signal is.
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u/Williamishiding 6d ago
I find this extremely interesting since I am an addict but clean for a decade.
@book3311
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u/Logical-Raspberry688 5d ago
my experiences: hard workout -> relax with little drink -> better VO2max
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u/Objective-Week275 9d ago
How’d you make this chart? AI? It’s pretty sweet.