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MRI scans show exercise can make the brain look younger (sciencedaily.com)
121 points by amichail 1 day ago | hide | past | favorite | 52 comments




> brains that looked nearly a year younger

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.


>But it just begs the question, if you think that then go measure those things with your study.

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


Many such effects compound with time, and every additional year of regular exercise adds compounding benefits in multiple systems across the physiology.

> 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.

Man, this website sometimes...


The 150 minute moderate to vigorous exercise a week comes up a lot, and for a lot of different benefits.

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-...


This is from the abstract: Engaging in 12 months of moderate-to-vigorous exercise reduced brain-PAD in early-to-midlife adults. The pathways by which these effects occur remain unknown.

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.




Neat study, but I always chuckle at these, because has there ever been verified science that shows exercise is unhealthy? (besides overtraining)

The general consensus should just be exercising is good for you, that's it, done.


And I chuckle at these types of comments.

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.


>... has there ever been verified science that shows exercise is unhealthy?

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.)


You could look at the inverse: Not exercising causes the brain to look older. Knowing all of the ways not exercising is harmful is probably a good thing.

But I agree, it would be better if everyone exercised!


Good point, but has anyone shown that gravity doesn’t work in general relativity conditions? We move the needle of proof, such that the burden to disprove becomes harder. That seems fine by me, it’s nicer and nicer to see the benefits of exercise.

That’s awesome!

The benefits of exercise against aging, mental illness, etc are numerous and well documented. Everybody should do it.


> 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.


Have you looked into Long Covid? Post-exertional_malaise is something a lot of people are reporting.

https://en.wikipedia.org/wiki/Long_COVID https://en.wikipedia.org/wiki/Post-exertional_malaise


That's not normal. I'm sure your doctor's told you that too.

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.


> I think you might be able to push through it.

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.


The person I replied to said they were taking it easy. 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.

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.


They said:

> 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.


They also said: > Very short distances, very slowly and very gradually.

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.


I kept pushing running and cycling for a couple of months. I had to stop because it was making me feel too bad. I replaced it with hiking, walking and some misc exercises like stairs stepper. I kept that for another couple of months but eventually crashed even with this lighter effort.

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 hope your doctors clear you for exercise again and you feel comfortable giving it another go (after sufficient rest and recovery from this experience).

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 really isn't normal at all, just for the record. There is definitely something seriously wrong

If that was true athletes would be the youngest, mentally healthiest, and in many other ways better than average. But that's not the case if you look at them. My guess exercise is beneficial only to some level, after that it has a big toll on everything. Including IQ, mental and general health, and so on.

>My guess exercise is beneficial only to some level, after that it has a big toll on everything. Including IQ, mental and general health, and so on.

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/

[2] https://www.pnas.org/doi/abs/10.1073/pnas.2415126122

[3] https://pubmed.ncbi.nlm.nih.gov/38729629/


It is the case, actually.

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.

https://pmc.ncbi.nlm.nih.gov/articles/PMC11979035/


Being an athlete and doing maintenance exercises are two different levels of exertion.

They are. Fit people are generally just better than unfit people in almost every way. More physically capable, fewer heath issues, more energy, more attractive, more disciplined, more intelligent and so on. Some of those are probably not entirely causal, for example bad health can prevent exercise. Lower intelligence is correlated with obesity. Getting fit takes discipline but it also builds discipline.

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.


Mike Ohearn.

Less wise perhaps.

Can exercise make the face look younger? Or the body? Is exercise the best makeup? ;-)

Running makes you look older, unfortunately.

Cycling too.

The standard being 20kgs under weight, skin baked like old leather, and a previously broken collar bone.

But, nothing beats it.


Wear sunscreen? It's necessary to not age fast if you go outside often. And moisturizer and retinol if you'd like too.

I wish it were that simple. I’m of Scottish and English genes. I wear spf 50 and still get burnt in the savage New Zealand sun.

I try to go early.


So this is why 30/40 yo track athletes look older than their age mates? Right.

Nonsense. Running at an Olympic level and pushing the boundaries of what we've evolved for might leave its mark. But that is not what is being talked about here.

There seems to be abundant evidence that exercise is often the best solution for any number of things.

The problem is that doing it sucks.


Doing boring rote movements sucks. There are lots of fun ways to exercise.

Exercise doesn't suck, land use policies generally just don't prioritize good places for the fun kinds of exercise.

Who does land use right?

I can criticise Australian urban planning for days ... but many visitors to Australia do effuse about how much outdoor recreational space we have and plan for.

Eg: Perth's 7km park: https://www.facebook.com/reel/1362227242068763 and https://www.tiktok.com/@9newsperth/video/7553237387548134712

AU Aintree North Recreation Reserve : https://www.youtube.com/watch?v=k5vYNG2eL9g

Skate parks, woops, river and coastal setbacks: https://www.youtube.com/watch?v=HfLa32K74Zw


Yet Australia’s obesity rate is around or worse than that of most of the Western states, Minnesota, Missouri and Illinois [1][2].

I don’t think land-use policies are the main cause.

[1] https://data.worldobesity.org/rankings/

[2] https://www.cdc.gov/obesity/data-and-statistics/adult-obesit...


First link has Australia, the country, at 32% obesity Vs. USofA at %41.6.

My only observations, having travelled in both, is that Australia like eveywhere has gotten more urban in past 20 years and I've got a feeling the percentage of Australians significantly past the technical bar of "obese" is very low compared to rates in the US of "well past" "just merely obese".

I'm not sure anyone's broken down the obesity quintile demographics.


Why are you excluding the heaviest 2/3rds of the US population from your comparison?

> The problem is that doing it sucks

I really dislike running for running's sake. But I love inline skating. Did a 20km route yesterday, did 43km a fortnight ago (which was admittedly too far for where my stamina is at). One of the things about skating (and this would also be true for cycling) is the different perspective it provides if you normally get around your local area in a car. You get to see the same places from radically different angles, depending on what paths are suitable to the mode of transport. Just going slower on or next to the road you get to see more detail, but footpaths and other tracks are often (possibly not the right terminology, but) 'off the beaten track'. In inner suburban Melbourne (whilst holidaying there) I chanced upon a relatively unpopulated footpath alongside a river / drain that took me 15km into the city, and it was (in parts) both peaceful and beautiful, despite really not being that far away from main roads / highways / freeways.

A lot of people like cycling, can be done individually or in any sized group.

Tennis is mostly individual (although an opponent is required), but I play in a team and enjoy the combination of singles, doubles, and an overall team result.

Football, soccer, rugby can be physically brutal, but are team sports that have a (forced) social aspect if that's an unmet need. Volleyball is a bit less intense. Table tennis. Lots of options for different sports that cater to different levels of physical stress.

Find a local park that has a basketball ring and just shoot hoops with yourself regularly. It at least gets you out of a chair and moving both arms and legs.

If you don't (think you) like any of those things, then you gotta do the hard yards to find that one rare thing you do like. It could just be something that you can find an appropriate level of progression that gives you 'that feeling'. I think that's what got me into skating late in life - I was terrible at it as a kid, but kinda forced into giving it another go as an adult, and within a couple of hours I was already better at it than in my childhood. It was a sense of accomplishment achieved in a relatively short term (= addicted? maybe).

Find your healthy addiction.


Kettlebells are the perfect middle ground for me. Dynamic movements, easy to incorporate strength gains, very little floor space required and one kettlebell is enough to get started. After a few years of kettlebells I feel like my lower back is made of titanium.

Downside is there is a fairly steep learning curve to use them without injury.


Find a better way of exercising.

There is something out there that suits, surely. Sometimes it’s just a step removed.


And importantly: stick with it for a few weeks before deciding whether you enjoy it. Virtually no one falls in love with the gym (or whatever fitness activity) the first time they walked in. Getting started isn't always fun. But over time it can become very rewarding.

> stick with it for a few weeks before deciding whether you enjoy it

I think this can be bad advice for people who may be predisposed to dislike exercise due to past experience or just straight up unfamiliarity.

More constructive is to think about what you don't enjoy about the activity and whether those are intrinsic qualities or can be changed. If they can be changed, change them.

Similarly, it's a good idea to think about things you know you enjoy that can be coupled with exercise. Add those things to your exercise environment to build up positive associations over time.

As a simple example: if you feel self-conscious about your body when you go to the gym you shouldn't try to just suffer through that feeling. Just workout somewhere where you don't feel self-conscious.


Play soccer twice a week. It's high intensity cardio, normally 60-90 mins tops. Sometimes beers after. And actually fun. Even in a coed league or an adult (min age) league. It's a great time. Bonus points - you'll possibly look more athletic if you keep at it long enough and don't over indulge in those beers!



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