The effect of physical fitness on mortality is overestimated

My university required a swim test to graduate, and also required 10 minutes of treading water in order to access sailboats. Many of my classmates talked about this being difficult, but both were trivial for me.

Fat is buoyant.

I could see a scenario where less fit people stay out of the water while people who are fit do more activities in the water and some of them engage in riskier activities in the water like whitewater kayaking.

fit people swim, fat people float?

Those studies never 'control for those'. What they do is a crude statistical approximation (sometimes extremely crude - eg most studies will 'control for education' by counting up 'years', which equates 4 years at Caltech with 4 years in community college), and hope that not too much leaks through as "residual confounding" (https://journals.plos.org/plosone/article?id=10.1371/journal...). Unfortunately, because everything is correlated, there's residual confounding everywhere. This is why every time someone does a Scandinavian population registry study and compares eg siblings within the same family, often the correlation just disappears then and there.

It's 100% unsurprising that this is true of fitness too. This is what always happens. You look at something like a corporate health fitness plan and you find some correlate even after you 'control for' SES, prior health record etc etc; wonderful! Then you do a randomized experiment and it turns out that the residual confounding was still larger than any causal effect which might be there: https://gwern.net/doc/statistics/causality/2022-wallace.pdf Ah well. Maybe next time you'll manage to 'control for' the confounders...

> It might be co-causal

Kinda like how wine after dinner improves health outcomes. The kind of people who can afford to regularly drink wine, but not a lot, also have more access to healhtcare.

Also riding horses makes you healthier! (it’s a proxy for wealth)

One could argue that high VO2max may just be another proxy for wealth. People who can afford to work out every day can also afford lots of other things that correlate with health and longevity.

Your comment ignores the main point of the comment you are replying to: namely, a lot of reporting on studies that find that some intervention increases lifespan ignore strong evidence that the same intervention fails to increase (or worse, actively decreases) healthspan. A diet low in protein for example, will tend to increase your lifespan while tending to make you one of those 70-year-olds (or 60-year-olds if you're unlikely or maintained a diet very low in protein) with very little muscle left -- and no way (that we know of) to regain muscle: at that age, neither exercise nor increasing dietary protein quantity and quality will significantly increase muscle mass even if muscle mass is very low.

I suspect that something similar can be said of not doing enough exercise.

We are commenting on a press release from a university, i.e., written by professionals whose job is to increase the prestige of their employer. It is rich for you to criticize Peter Attia, M.D., and ignore that little gem. At least Attia is trying to understand some aspect of reality more fundamental than impression management and increasing the public's awareness of whatever their employers tasks them to target.

I've read Attia's book, and all he said there about diet was that it was really hard to study, but the best study he knew of made the Mediterranean diet look pretty good.

He went into quite a bit of detail on exercise though, focusing on the predictable ways you'll lose capability as you age, if you don't work really hard on avoiding that.

Which study are you referring to for keto having a negative impact on cardiovascular health? I've unfortunately found studies and metastudies reaching all sorts of conflicting conclusions on keto.

The top metastudies on a simple google search both conclude positive effects on CVD.

I thought the whole trend of "healthspan" as a word was a direct response to / attempt to sidestep the many people who are convinced that any artificial increase to "lifespan" will doom humanity to either Tithonus or Altered Carbon and will fight you over it if you dare propose such a terrible, terrible thing.

> Nobody wanted to live a long time but be unhealthy in their older years.

If nobody wanted that, then why have we spent so much effort keeping older people alive and in agony for a couple more days, often in direct opposition to their preferences and DNRs?

If nobody wanted a medical system that caused such suffering for such little reason, then how come the excellent How Doctors Die[0] needed to be written?

[0] https://www.saturdayeveningpost.com/2013/03/how-doctors-die/

I think that at best the jury is still out on Rapamaycin. It has healthspan- and lifespan-increasing effects on most animals studied.

Bryan Johnson quit using it, but he’s on 40 other things and there are bound to be drug interactions.

That said, limiting consumption of health and fitness influencers is bound to be good for lifespan: you’ll have more time to live.

And yes, it’s hard to make a living as an influencer saying “eat food, mostly green, move your body, and spend time with friends and loved ones.”

Exactly. And if you consider that every hour you spend purely exercising (gym, treadmill, etc.) in the middle does NOT pay for an extra hour of life on the tail end, it doesn’t seem like the best trade.

(I will say that a morning workout still supercharges your day!)

Posterior cortical atrophy:

https://en.m.wikipedia.org/wiki/Posterior_cortical_atrophy

PCA can cause simultanagnosia and other problems with visual perception.

Have you ever seen an elderly person drive directly at you in a parking lot, at low speed, and appear to be completely unaware of your presence? This could be why.

Can’t post a car ride on Strava.

You live closer to work?