The Right Dose of Exercise for a Longer Life | Hacker News Reader

The Right Dose of Exercise for a Longer Life

well.blogs.nytimes.com

162 pointslxm52 comments

I always wonder to what degree this kind of study might invert causality: that is, people who are subclinically "ill" may be less likely to exercise in the first place because it is harder or less pleasant for them. Someone with, for example, undiagnosed but significant cardiovascular disease (unfortunately very common: in many cases the first sign anyone recognizes as concerning is a heart attack) is likely to have some degree of decreased exercise tolerance and discomfort at longer durations and intensities -- and thus will be less likely to meet the recommendations.

Or indeed other causes which could create an accidental correlation. The more you eat the fatter you're likely to be, the fatter you are the harder exercise is, the less of it you're likely to do. The more you smoke, the more out of breath you'll get when exercising, the less of it you're likely to do.

These are two examples I personally feel contribute to my not getting as much exercise as I did 10 years ago. If I die early is it that I haven't exercised enough, or that I had an unhealthy diet and smoked a lot of cigarettes? (I'm not saying lack of exercise doesn't contribute, just that picking it out on its own doesn't necessarily show the full story.)

Additionally, given how well-known the basic concept of "exercise is healthy" is, I would imagine there would likely be some correlation between people who exercise specifically for that purpose (rather than because they enjoy it) and who also take other steps to stay healthy (whether that's having a good diet, or taking vitamins, or.. whatever).

A well-run study should control for weight and smoking. But the undiagnosed cardiovascular disease can't be controlled for. Exercise is much harder for me than for others, for example, and I don't know why.

You can only control for weight and smoking if you have good data, which is to say that at least a significant portion of the weight and smoking behaviours are not causally linked to the exercise behaviour. If the data is not sufficiently diverse, no amount of statistical power will overcome the garbage-in garbage-out nature of regression.

Do your lungs/throat clog up or shut down? It could be asthma, or, more interestingly, subclinical cystic fibrosis. (CF requires a mutation on two genes, and it's very apparent even from childhood when you have the full form; but there are phenotypic differences in people who only have one of the mutations, such as being resistant to some parasites which are blocked by mucosal thickening(!). The implications of the single-mutation variant on health, though, are AFAIK completely unexplored in medical literature.)

No, my heart rate goes up (like everyone else's) but doesn't come back down for a while (10 minutes?). I have no endurance and resting between workouts doesn't recharge me.

Completely anecdotal but low blood sugar does that to me.

Having a good sleep and some sugar before improves the condition.

Random reply from someone on the internet: Do no take this as medical advice :-)

Obviously, Your two sentences is probably not enough for me to help you, but I'll give it a shot anyway. Having a high heart rate that you can sustain is, in my experience, actually good for endurance sports. In fact, my father pointed out the other day that he just can't get his heart rate up any more (he's 73 and still rides his bike over mountains). This means he can't get enough oxygen into his muscles to keep a high pace. As I've grown older, I've also noticed this ceiling that is limited by how high I can sustain my heart rate and for how long.

So, rather than assume that your observation is the problem, I think perhaps you might have something you can work with, whatever your underlying problem actually is. I've done sports my whole life (running, a small bit of weight lifting, karate, and now cycling). Especially now that I'm getting older, I need to concentrate on "base miles" on my bike. This means going out at a very slow pace (annoyingly so, for me) and riding for very long time. Cycling is good for this as it is relatively easy to dial the pace to whatever you need -- just make sure to have a lot of low gears if you tend to have problems.

I suspect that if you ride a bike at a very slow pace for an hour a day for about 6 months that you will find a really marked difference in your ability to exercise. Keep your pace so that you could have a conversation easily and that you aren't out of breath. If you run into difficult situations (hills, wind, whatever), just go into a lower gear. You may need to go to a bike shop to get especially low gears, but it won't be outrageously expensive.

Hope that helps.

Hypertension, perhaps? Or some sort of adrenergic overproduction that could be treated with beta blockers.

3% of white people in the U.S. are affected to varying degrees by a genetic disorder called a Alpha 1 Antitrypsin Deficiency. I found out I had the moderate form(SZ) from 23andme.com. I've never been able to exercise as well as anyone else.

It is a genetic liver disease that causes harm to your lungs.

"Exercise is much harder for me than for others, for example, and I don't know why."

genetics can partially account for the lack of improvement after training, one specific gene "alpha-actinin 3 (speed gene)". The other component is environment.

    Why is it that some people respond better 
    to training than others? Are you a sprinter 
    or a marathon runner?

http://www.abc.net.au/catalyst/stories/4132778.htm

You're not the first to wonder about this. http://www.ncbi.nlm.nih.gov/books/NBK62370/ "It should be noted that while these results may reflect the effect of exercise patterns on mortality, reverse causation is also possible—that the results reflect instead the effect of health on physical activity."

But what if you studied people who made a decision to change their exercise habits, and checked if it made a difference in general health?

That would seem to be subject to the same basic problem; whether people make a decision to add exercise may well be strongly affected by their experience with activity eighth may be affected by the same kind of subclinical condition that itself is a mortality predictor discussed up thread.

Of course the potential for such inverted causality is a cause for developing and testing hypotheses about the alternative explanations, not a reason to casually dismiss the study or the more obvious conclusion on the causal relationship.

Note that the biggest reduction in mortality was found in people who walked for an hour a day. Yet that group probably contained the most of what you call "subclinically ill". After all that's one of the easiest forms of exercise and there is a higher likelihood it will be chosen by people with health problems, diagnosed or not.

Causality often gets confused particularly by the time the results make it to the popular press. Studies of alcohol intake against mortality often show the effect. Scientists find drinkers drop dead slower than non drinkers, the the newspaper reports it as a glass of wine a day protects your health. The reality is people like drinking but you've got to be reasonably fit to take the damage it causes.

Anecdotally, yes, I think you may be on to something.

For example, I suffer from persistent but relatively mild skin problems which make getting the right amount of exercise difficult without causing more pain.

I know I walk less than I should do, but I can't do more without causing more problems for myself.

A very important detail - these are survey studies: "Of course, these studies relied on people’s shaky recall of exercise habits and were not randomized experiments, so can’t prove that any exercise dose caused changes in mortality risk, only that exercise and death risks were associated."

NOT Randomized controlled trials.

So take these with a pinch of salt and then go outside & run for 30 mins every day.

>The sweet spot for exercise benefits, however, came among those who tripled the recommended level of exercise, working out moderately, mostly by walking, for 450 minutes per week, or a little more than an hour per day. Those people were 39 percent less likely to die prematurely than people who never exercised.

This is like that one TED talk on longevity that found green zones where people lived much longer. One factor found in these people's lives was an ambulatory day, just generally walking a lot -- but, surprisingly, none of these groups went out of their way to exercise.

I wonder if we integrated regular walking into our city planning that we could reduce cardiovascular disease and obesity.

That seems difficult for a sedentary adult living in suburban America who drives their car to work and sits at a desk all day, but for cultures that do more walking - ie in cities that are more laid out for walking and public transportation - an hour of walking per day is almost an afterthought. In Dubrovnik, Croatia, for instance, a small city largely built on the side of a mountain (https://moremojitosplease.wordpress.com/2012/06/25/dubrovnik...), I've never done so much cardiovascular exercise inadvertently just by living there for a week. I also noticed that very few people, if any, were overweight. In fact most cities I've been to in Europe seem to be quite good for walking. The ramifications of this study should certainly be factored in to city planning.

Now we need someone to combine these two to give us a picture the whole parameter space. Wouldn't a 3d graph by awesome here? Premature death rate on the Z axis, minutes of weekly exercise and percentage that is beyond a given intensity threshold on the X and Y? You could then compare that to the same thing, except using average intensity as the metric instead of amount of time spent over a threshold.

450 minutes per week was optimal when it was mostly light exercise, and intense exercise is more beneficial, with diminishing returns after 30 minutes per week. But if you do a higher percentage of intense exercise, does the optimal time per week decrease? (Or maybe even increase as you get beyond a certain fitness threshold! Although I somewhat doubt that.)

Reading the abstracts, the measurement the US study uses for "dosing" is metabolic-equivalent hours per week. The Australian study uses "vigorous".

If you want to grade your activities of choice to METs, there are various sources to do estimate them:

http://en.wikipedia.org/wiki/Metabolic_equivalent

Studies like these always make me think how little we know about human body. I wonder when are we going to stop doing these kind of studies and learn from human body as purely engineering system. By simulating it at a molecular level and understanding it that way.

Where are the chips that mimic cells and help create complete simulation of a trillion+ cell system? We need Elon Musk of human body :)

How about simply being able to better monitor/measure changes in the body?

How about that.

Changes of what? There are millions of parameters that affect each other in a nonlinear fashion due to genetics, environment, diet etc. Getting such data from the living system would be prohibitively invasive, blood tests have their limitations and doesn't provide real-time data.

I don't know what can be or should be measured. The idea is to develop better techniques for monitoring the body. A future tricorder X-Prize, for instance: http://tricorder.xprize.org

You're telling me what we can do today. I'm asking what we can develop to solve the problem.

> simulating it at a molecular level

It's a work in progress

http://large.stanford.edu/courses/2014/ph240/milic1/

Eukaryotic cells are much more complicated though. It has been estimated we have done 1% of the biological experiments necessary to figure out how a human actually works.

Anybody want to fund my prostate cancer biomarker discovery project?

> Anybody want to fund my prostate cancer biomarker discovery project?

Only if you'll fund my endometriosis genome study (I need 25k participants) and the resulting CRISPR/Cas9 gene variant protocol trials ;)

Speaking of CRISPR, how big of a discovery/invention is that ? Is it going to change medicine forever ?

CRISPR is revolutionary, and apparently dangerous enough that some researchers are advocating for it to be disallowed.

I'm glad we're getting a better understanding of how much these variables contribute toward longevity and well-being. Now we just have to come up with a plan to deal with the challenges of people living far longer.

I don't know if I'm alone in noticing this, but there appears to be a larger divide in society along these lines opening up. More people seem to be exercising than ever - almost every guy I know has a gym membership, is taking part in a sport, or goes hiking, or whatever - where previously the same people may have been thin/healthy but sedentary.

On the other side of things, it appears that more people seem to be simply getting more fat and more sedentary. Where once there was thin/average and sedentary | mildly overweight and sedentary, it seems to be dividing to thin/average and pretty active | very fat and very sedentary.

That is all from personal observations, but it will be interesting to see the physical composition of society in 5-10 years time. What was once overweight has simply become normal, what was "fat" has now become huge and what was once a healthy weight has become the new thin.

> More people seem to be exercising than ever - almost every guy I know has a gym membership, is taking part in a sport, or goes hiking, or whatever - where previously the same people may have been thin/healthy but sedentary.

That's because more of our interactions are moving online than offline so you see people at their best and not how they typically are. ;-)

When this subject comes up, I always think of this article: http://startingstrength.com/articles/barbell_medicine_sulliv...

For me it always comes back to: what are people's long, long term goals. Overall? Is it a longer life? Do you want to live an extra five years? I personally don't think that's a good goal. I'd much rather be in good shape, mobile, healthy and relatively pain free for my 30s, 40s, 50s, 60s and as far into my 70s as I can manage than to increase my lifespan from 85-90.

It's way less about eking out a few more years of keeping death at bay and way more about feeling good while I'm a mobile, mentally healthy adult.

Yes, I want an extra five years. I'm working on a difficult project that I might not finish before I die. Five more years would really help me.

"Duke Nukem Forever: Part Deux" developer spotted.

Young people say this a lot, but I don't hear people in their 80s say it.

When my grandpa was dying in his mid-80s, it really hit home for me how scary it is. Even if you've had a fulfilling, long life, dying still sucks. For young people, another year of life for an 80 year old doesn't seem like much, but to an 80 year old it means the world.

> Young people say this a lot, but I don't hear people in their 80s say it.

When you are young those five years don't look that attractive: you are older, slower, half your friends and family are gone, you might not have any money to support the life you want depending how the economy goes, and so forth - so having a bit more fun now seems like a good compromise. Once you get older then you realise that any time is worth having as there are still more things you want to do and more time you want to spend with people than you might have time for left.

Of course having too much "fun" now means that your old decrepit years come sooner because your body will fall apart faster, so that really isn't the good compromise is might seem to some - you start paying in good years as well as the later ones you might be dreading at this point in your life.

To be far far more flippant about it, my reasoning up to a few years ago was:

"My main worry is being able to afford to live a content life beyond a certain point so my current pension plan is to not live long enough to need a good pension. Hence my drinking habit: I'm investing heavily in cirrhosis futures!"

Having started to see some of my older friends in bad conditions, various people in my life having less serious but still significant health scares, I changed my mind about that quite a bit. Had I not decided to shape up back then, an old friend my own age (mid 30s) shuffle off to the crematorium rather prematurely recently might have made me do it. I might not care about those last few years in my 80s now, but I certainly care about hanging around for a good few years yet. I've got places to see and people to do!

Ahh, but do the people committed to dying young generally live to their 80s?

Beware selection effects in all things.

What part of the article gave you the impression that an exercise related reduced chance of death in a given year would cause a person to be in worse shape or less mobile/healthy/pain free? Your conclusion is counterintuitive, so I can only assume you have an interesting basis for your position.

I ask because a naive reader might assume that you're just making a dismissive middlebrow comment. Which would fall into the category of gratuitous negatively, and I can't imagine you'd be doing that.

He is not drawing that conclusion. He is just questioning people's insentives for staying in shape. You get longevity, but actually the great part is you feel better day to day. It's like telling a smoker to quit because he'll feel better day to day breathing and being able to walk longer without catching their breath rather than telling him to quit because he'll die of cancer.

Having a goal to live longer isn't too different than having a goal to live healthier. Living healthier and living longer go together, and you can't generally cherry pick.

Of course, if you want to reduce probability of premature death or permanent disability by staying away from dangerous activities and places, then that's a different conversation.

The trend overall in society has been that people are both living longer lives, and also have shorter periods of morbidity at the end of life.

Moderate exercise would seem to be helpful for both length and quality of life.

Have your cake and eat it too!

"Shorter periods of morbidity" surprises me -- where'd you get that from? (I would've guessed the opposite, from the stories of people kept alive in hospitals unpleasantly long, but I don't have data.)

Fortunately this study seems to say you can have your cake and eat it too.

Whether running or weight training, high intensity exercise is much more fun that moderate intensity exercise. I started going to a personal trainer to build strength and pushing myself when running, and not only is it more effective, it's a lot more fun.

If you're walking 6 miles or biking 15 miles a day to commute, maybe that's not such a great idea. It isn't that much fun, isn't really much better for the environment, and it might actually shave a couple of years off your life. That sort of constant exercise isn't going to be very intense.

Five more years of life is five more years for the current state of the art to work on giving you another five years after that.

I think a lack of exersize throughout the day is why guys today are going bald earlier than in previous generations. I think high intensity exercises for 3 min every 1-2 hours throughout the day is reversing my hair loss. I'll be making a blog post on it soon with evidence of my progress.

Since August of 2014 I had been losing my hair. More and more of it was showing up in the sink drain. Earlier this year I got worried because it increased. I wasn't sure if it was a temporary thing due to stress or illness so I started saving up the little clumps of hair between paper towels and date stamping them. It just kept getting worse and worse. I got a blood test to check hormone levels and find out if everything's ok. I'm waiting on the results.

Last month I got tired of it all, and decided to experiment as a last ditch effort to prevent baldness in my late 20s. I started short but high intensity exersizes every 1 hour, for about 2-3 minutes. After only 1 week new hair has started sprouting up on my scalp. And the amount I've seen in the sink drain has gone down drastically. This is very odd because there's a huge delay in when hair grows and falls (often months) not 1 week. So I'm convinced it's the exersize that's increased circulation, jump started cell growth, and maintained healthy hormone levels. I need to test this out in the long term and try to get other guys to participate. I doubt it's a coincidence because 1 week I skipped my exercises and my hair growth decreased a bit and hair loss increased a tiny bit.

tl;dr The right dose of exersize for a healthy head of hair. Possibly.

I started losing mine at 17 and I worked out/moved a lot at the time (played 2 sports + fun activities) so I doubt there is a connection there.

Your single point of data (anecdote) isn't really any more useful than his. I know at least one very old person who has smoked all their life, for example.

Male pattern baldness is directly linked to testosterone. I believe is also linked to stress. If you're TOO active and causing high levels of cortisol in your system then you'll probably go bald early.

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