Posted by amichail 5 days ago
Seems like a pretty small effect - if I'm 58 and I have the brain of a 57 year old, and to achieve that I did an entire year of exercise (as was done in this study) ... you'd have to evaluate it against many other things to decide if that was really the easiest way to achieve that result.
I'm always suspicious of small effect sizes even when they are statistically significant. It just seems like so many confounders could bring about the effect. Here I'd wonder if just the mental challenge of achieving that sustained exercise over a whole year was responsible, since generally speaking, any mental challenge you undertake on a regular bases improves overall cognition.
They try to argue their way around this:
> "Even though the difference is less than a year, prior studies suggest that each additional 'year' of brain age is associated with meaningful differences in later-life health,"
But it just begs the question, if you think that then go measure those things with your study.
Of course I'm not in any way arguing against exercise. Adding at least a baseline level of exercise into your lifestyle is the most impactful health intervention anybody can do after age 40 I believe.
Because randomized control, multi-year, longitudinal studies into behavioral interventions in human beings are incredibly annoying and expensive to run if you want to account for the risk of drop outs and/or non-compliance. They hosted twice weekly aerobic exercise classes for the experimental group (dozens of people) for a year! That’s not cheap by any means
Man, this website sometimes...
There's also heart muscle elasticity:
https://www.ahajournals.org/doi/10.1161/circulationaha.117.0...
and reduced dementia risk:
https://publichealth.jhu.edu/2025/small-amounts-of-moderate-...
They do not make the claim from the title. Given that the effect is small, it might just be that brain-PAD is sensitive to other factors than age, e.g. exercise. As a matter of fact, this study is decent aupport for that hypothesis.
The benefits of exercise against aging, mental illness, etc are numerous and well documented. Everybody should do it.
34 years old male, not overweight, eating healthy. I kept reading that exercise is the best thing you can do and that everyone should do it, so I started running and cycling. Very short distances, very slowly and very gradually.
It made me feel horrible. Each time it would take me a few days to recover, feeling dizzy and mentally exhausted. I thought that I was just a bit out of shape so I kept going. Big mistake.
A few weeks ago I completely crashed with the dizziness and mental exhaustion staying constantly, leaving me unable to do basic things like standing for more than a few minutes at a time. Complete rest helped, after a few weeks I finally start to feel like myself again. Currently seeing doctors and doing a lot of checks, nothing obvious found so far.
The only reason I kept pushing is that I was reading everywhere that exercising is this amazing thing that is good for everyone. So at the moment I feel that this messaging should be toned down a bit.
PS: Long time HN user, using a throwaway as I don't want health stuff to be tied to me.
My first thought is that it may just be a severe case of being out of shape, I think you might be able to push through it. You didn't specify how long you kept it up but I would expect it to take at least a few weeks, maybe a few months before you really get up and running.
I would suggest that you keep trying, and taking it slower. Maybe instead of running and cycling just walk/hike. I find it much more comfortable to hike.
It's also useful to keep track of your pulse. There's a type of training called zone 2 training where the goal is to keep your pulse in "zone 2". That's quite low intensity training, but it's also very effective and much less taxing. Zone 2 depends on your resting and max pulse but it'll be something like 130-160.
I can also recommend rock climbing, particularly bouldering is very approachable. And of course weight lifting if that's more to your liking. You don't have to do cardio, there are many ways to be active.
I have had some issues with nausea while weightlifting, towards the end of a session I would get really nauseous. However that's just me being out of shape, after a week or two it subsides and it just feels good. I like the feeling of sore muscles.
Also, for me, activity is essential. When I'm not active I fall into a deep depression where everything feels harder. When I'm in shape I feel like myself, I have more energy, motivation and discipline, life feels easier. I don't think it's like this for everyone but I do think everyone benefits from exercise. Even if you have to fight through some bad feelings to get going.
Zone 2 while running and cycling was absolutely impossible for me. A light jog would make my heart rate climb to 190 bpm immediately. A small couple of percent incline on a bicycle, straight to 190 bpm. Obviously feeling horrible afterwards.
These last few weeks my resting heart rate went from ~60 to ~100. I saw two cardiologists, none found anything out of the ordinary. Got some beta blockers for the heart rate, which do work so at least I got that working, but no indication of what the actual problem is.
Which is too bad because besides feeling like shit afterwards, I actually enjoyed these activities a lot.
I had a similar - but less extreme - experience in my early 30s when I decided to start exercising after 20+ years of highly sedentary living. I somehow convinced myself that my heart rate being >160 while in "zone 2" was normal for me. In truth, what seemed like impossibly light exercise (5-10 minutes of "zone 2" every day) was too intense for me at the time. I burned out after about two months. It was very humbling to realise that the elderly people who jogged in the park near my apartment were more physically fit than me, and it took me a while to accept that.
When I eventually started exercising again I began with an intensity roughly equivalent to walking on a flat surface (HR around 105-115bpm) and stuck to a simple rule of thumb: if I didn't feel fully recovered 15 minutes after finishing a workout I had pushed myself too hard. From that baseline I was able to occasionally do a more intense effort, paying close attention to my heart rate during the workout, and being very mindful of what my body felt like during the effort as well as 15 minutes after, later that day, and the next morning. Over time I was able to ratchet up the intensity of 2-3 efforts per week and still feel fully recovered. After about a year I could do 3-4 genuinely hard workouts a week with a low risk of overtraining or burnout.
What I would point out is that in your original comment you said:
> I started running and cycling. Very short distances, very slowly and very gradually.
So from your perspective these were appropriate efforts. But then you go on to say:
> It made me feel horrible. Each time it would take me a few days to recover, feeling dizzy and mentally exhausted.
> A light jog would make my heart rate climb to 190 bpm immediately. A small couple of percent incline on a bicycle, straight to 190 bpm. Obviously feeling horrible afterwards.
These are really strong indicators that you were pushing far too hard.
That a light jog would be far too hard for a 34 year old is very confronting. It's a huge blow to the ego. I've been there, and worked my way out of the hole. Assuming there's no underlying medical condition I think you can too.
This is really awful advice.
People who are extremely unfit tend to have no frame of reference for what a productive workout feels like. They are highly likely to push themselves too hard and then not give their bodies enough recovery time. Encouraging people in this situation to "push through it" is setting them up for overtraining leading to injury, illness, or burnout.
Fatigue is one of the most important signals your body can give you. It's a clear communication that you've been pushing too hard and need to reduce the intensity of your efforts. Telling people to ignore that signal for "at least a few weeks" is at best going to be counter-productive for them and, at worst, dangerous.
I wasn't intending to suggest anything remotely in the same ballpark as overtraining, that's not the kind of pushing I had in mind.
And when they clarified that they had been doing it for months I just said that's not normal, because a couple of months is beyond the scope I had in mind when I suggested pushing through it. It shouldn't take months. What they describe sounds more like a serious undiagnosed health issue.
> It made me feel horrible. Each time it would take me a few days to recover, feeling dizzy and mentally exhausted.
That doesn't happen with a genuinely easy effort.
> By push through it I meant keep it up for a while longer even though it made them feel unwell, thinking they would get past the unwellness.
Yes, that is really bad advice and will lead to overtraining in a very unfit person.
> I wasn't intending to suggest anything remotely in the same ballpark as overtraining, that's not the kind of pushing I had in mind.
I don't know what you mean by overtraining, but pushing through feelings of unwellness or fatigue and continuing to workout is exactly how you get into that territory.
Which does not sound like overtraining to me. Any relatively healthy 30-something should handle that just fine no matter how untrained they are. They should get over the feelings of unwellness etc after a few weeks or at least a few months.
There is clearly some underlying condition causing this, it's not overtraining.
Are you basing that on anything other than vibes?
> There is clearly some underlying condition causing this, it's not overtraining.
Two cardiologists were unable to identify an issue, and their reported symptoms match OTS pretty much exactly.
https://en.wikipedia.org/wiki/Long_COVID https://en.wikipedia.org/wiki/Post-exertional_malaise
What reason do you have for thinking this? As far as I’ve read, there’s no indication that athletes perform worse than the population average on any of these metrics.
Athletes outperformed non-athletes on standardized tests in a 2014 study of Texas high schoolers.[1] Professional soccer players/footballers outperform the population average on a variety of cognitive assessments.[2] Sub-4 minute mile runners have better longevity and lower risk of cardiovascular disease than average.[3] With the exception of contact sports like American Football which involve serious risks of injury, I can’t think of any example of elite athletes that are worse off on quality of life metrics than average people.
[1] https://pmc.ncbi.nlm.nih.gov/articles/PMC4831893/
https://www.sciencedirect.com/science/article/abs/pii/S00256...
Here's another study, although for some reason it's 95% male, it shows athletic men live an average 3.5 years longer. It also shows athletic women live 0.7 years less, but due to the low number of females in the study I wouldn't read much into that.
So yeah I'm pretty sure that if you compare 1000 fit people and 1000 unfit people you'll see a very clear difference in happiness, health, success in life etc.
We're not made to be sedentary.
The general consensus should just be exercising is good for you, that's it, done.
Yes, the extremes of endurance have certainly been shown to have a negative effect on heart health, and possibly also colon health, but the amount of exercise required to get into the danger zone here is so high almost no one that isn't a competitive athlete would achieve it. (Although, amateur marathon runners might.)
But I agree, it would be better if everyone exercised!
We know that exercise is good for us, but studying it is how we better understand the different ways it is beneficial for us in a controlled setting.
I see these comments online a lot, just because something might be common knowledge, doesn't mean we fully understand it, nor should be stop studying it.