When you work a physical job you are typically working for 8-12 hours straight with little break and you often do repeated, but non-ergonomic activity that leads to joint damage such as standing on hard floors for 12 hours; bending over repeatedly with poor form to pick up a heavy tool; kneeling on hard floor; etc. Often, because of the long hours and fatigue, individuals resort to bad form to rest their tired muscles.
Working out for leisure activity, however, is often higher intensity for a much shorter period of time and typically very controlled ergonomically to reduce joint stress / wear. Professional and enthusiast lifters know that when you can no longer maintain proper form you stop lifting. Runners train and build their bodies over a year or more to handle up to marathon distances. When it is your occupation you don’t have such a luxury, so bad form happens immediately and repeats for an entire career.
Further, people who work out are usually making a conscious effort to improve health and make dozens of other small decisions such as improved diet and hydration that would be difficult to account for or control in a study. A nurse, plumber, or construction worker may be in good physical shape and making healthy choices or not. If they are not they are putting more physical stress on their body. A runner is making on e very clear healthy choice that probably correlates to a bunch of other healthy choices.
Also, people that have to work in laborious jobs are self-selecting for likely lower intellect, possibly higher dementia risk because of that.
If you want to take the brutal darwinian assertion out of it at a minimum there is a class selection filter going on and all the attendant medical care issues that come with it
It seems pretty likely to me that working a physical job late in life is correlated with lower income and wealth, which we know correlates to worse health outcomes. I would hope the study would control for that, but it's not clear from the article.
I would add that the physical exercise done during working is uncontrollable, at the difference of when going to the gym. The movements are extremely repetitive and have to be done even if it would be better to not do it
Plus, gym equipment is designed to be as ergonomic as possible (even something like a dumbbell is designed to be easy to grip and hold, contrast that with moving large, bulky equipment for a job).
Also, occupational physical activity often has exposure to harmful particulate matter and VOCs, such as in construction (or side: even the silicon fibrosis from rock shaping work recently discussed on HN).
I came here to say essentially that. The most I saw was "after adjustment," but it wasn't clear what that was exactly, and socioeconomic factors are such a large and obvious explanation they needed to address it clearly. Even if the referenced studies do, not bringing it up in this article is a red flag.
One thing to point out is that the study looked at Norwegians where while the wealth gap between high PA and low PA jobs is probably still significant it may be less pronounced than it would be in someplace like America or the UK. It still feels significant enough to be worthwhile to address though.
You apply the appropriate level of stimulus for where that person is currently and they exeperience positive growth. You apply too little stress and there is no adaptation or a reversal. If you apply too much, you get injured and go into reverse. I think this applies to any kind of challenge, be that physical like exercise, but also mental like learning, work, etc.
The more honestly you can evaluate where you are and what you can currently handle, the better you'll be. Don't be lazy but don't let your ego or dreams of being a big shot lure you into biting off more than you can chew.
There is a lot of wisdom in your comment. Sometimes things don’t make sense - don’t yield results despite all your best work because you bit more than you can chew
> "consistently working in an occupation with intermediate or high occupational PA was linked to an increased risk of cognitive impairment."
Translation from pseudo-scientific weasel-speak: if you don't have much of an education, and stick to manual job all your life, you will probably end up even dumber.
Connecting this to the idea of not all exercise being beneficial is cognitively deficient.
Exercise will not produce cognitive function. Lack of exercise will contribute to its decline, but you have to use your brain to train your brain. People don't exercise to get smarter.
Also, it's important to remember that cognitive function declines late in age regardless, the best thing to do is (1) keep being mentally active to slow that decline (2) build up cognitive ability as high so that you have longer to go before being severely impacted.
> Exercise will not produce cognitive function. Lack of exercise will contribute to its decline, but you have to use your brain to train your brain. People don't exercise to get smarter.
None of the studies prove that aerobic (or any other kind of) exercise actually improve cognitive function. It just restores the cognitive impairment from lack of exercise, similarly to fixing a nutritional deficiency.
Being sedentary is the aberration, not the historic norm.
Right?!? Plenty of highly intelligent athletes exist (countless examples from President Ford to Dr. John Urschel) but football helping them sit in the oval office or on the MIT Faculty probably had nothing to do with a boost in cognitive function.
I think what many people misunderstand about physical exercise is that it only works if you pair it with quality recovery.
You need quality food with good mix of macro and micro nutrients at a right time. And you also need good sleep and low life stress.
If you don't eat right or don't have good sleep or you are already in high stress (for example because of your job) then the results from your exercise will be limited.
Also, another point is that training is targeted exercise. You plan for the right kind of exercise, when it is good for you. Even if your activity does not seem like planned a lot like hiking -- you still plan for the hike to happen when you feel like doing it and you choose hiking that will satisfy you physically (not too much, not too little). When you do activity at work you rarely can control what you do and how much of it.
> consistently working in an occupation with intermediate or high occupational PA was linked to an increased risk of cognitive impairment."
I think this conclusion might be totally unwarranted: I suspect they did not control for how much the study subjects used their brain over the years of the study, let alone other correlates of jobs involving more physical labour.
The body has limits that can be expanded through training. However, exceed the limits and you will be injured. The key is to train up to your limits consistently.
Given that most jobs with PA in later life are low pay, I wonder how much nutrition and stress were factors.
This reminds me of the scene in Conan the Barbarian (with Ahnold) where he is taken a slave as a child and has to push a treadwheel till he is grown, the implication being that the slave labor was the reason for his heroic physique.
They found people in occupations requiring more movement had worse outcomes. But these people are probably also poorer, more stressed, drink more, smoke more. So it's hard to draw conclusions without controlling for this, to state the obvious.
I suspect the compulsory aspect of a job has something to do with it as well. When I injured my wrist, I simply stopped doing exercises that aggravated the pain. This is not really an option for someone whose livelihood depends on such physical activity.
Was going to say that. If it's done as a work, you _must_ do it every day, even when not feeling great, so you may lack adequate time to recover. I think adequate time to recover is the difference between exercise that strengthen us, and physical activity that just grinds us down.
Not to mention that those occupations are far more exposed to all manner of industrial chemicals and often have contempt for the precautions meant to keep them safe.
Just go to any construction site and observe how many are dealing with paints and solvents without any masks, let alone a properly fitted one.
You’ve been misinformed, as causality is not even within the purview of the experimental methodology of natural sciences.
In natural sciences, which include physics, you experimentally find that if you do X a few times, you get Z. That’s the extent of your hard claim. You can devise models that portray X as “causing” Z for simplicity, but the moment you start making claims about definite causal relationships you’d be making (implicitly or not) unfalsifiable claims about “underlying reality”, or in other words engaging in metaphysics. Maybe X causes Z, or maybe some unknown Y causes both you to do X and Z to occur—if you are evaluating a system of which you yourself are part, it is a fallacy to assume you possess complete knowledge about it.
That is simply not true except according to metaphysics. There are tests for causality in science which have no basis in metaphysics. This is why scientific conclusions about causality have thorough method sections and things like confidence intervals. A good paper is a discussion of eliminating alternative explanations. If new explanations emerge, you revise the paper.
Metaphysics exists (see what I did there?) because it says it does, not because science needs it somehow. We can’t take an existing paper and use metaphysics to add causality to it. We can only use metaphysics to weaken papers, and only metaphysically.
There are no tests that can prove causality due to reasons I outlined in my previous comment. Correlation can be reliable enough to be considered causation for practical purposes, but unless you possess some sort of transcendental sacred knowledge about the nature of the world you’re in, strictly speaking any “causation” is mostly correlation with a pinch of unfalsifiable pixie dust (or, more charitably, metaphysics).
A model, especially when described to a layperson, can offer various simplifications (such as electrons flying around their atoms like planets around a star, or X causing Z), but no one seriously considers a model as literally depicting reality.
An explanation with unfalsifiable claims is always slightly metaphysics.
Metaphysics, and philosophy in general, is how we have natural sciences, scientific method, reasoning, all those things. Dismissing it is not even wrong, it’s nonsensical because it’s not a sibling, it’s a parent.
If you read a scientific paper that talks about causation, you will see things like confidence intervals and assumptions. That’s what causality means, causal with some confidence under some set of circumstances and preconditions. That’s what science is.
Working out for leisure activity, however, is often higher intensity for a much shorter period of time and typically very controlled ergonomically to reduce joint stress / wear. Professional and enthusiast lifters know that when you can no longer maintain proper form you stop lifting. Runners train and build their bodies over a year or more to handle up to marathon distances. When it is your occupation you don’t have such a luxury, so bad form happens immediately and repeats for an entire career.
Further, people who work out are usually making a conscious effort to improve health and make dozens of other small decisions such as improved diet and hydration that would be difficult to account for or control in a study. A nurse, plumber, or construction worker may be in good physical shape and making healthy choices or not. If they are not they are putting more physical stress on their body. A runner is making on e very clear healthy choice that probably correlates to a bunch of other healthy choices.