10 ms·

The connection between exercise and brain health has now been super conclusively and astonishingly shown, but what are some possible evolutionary reasons for th

by jey 10y ago

The connection between exercise and brain health has now been super conclusively and astonishingly shown, but what are some possible evolutionary reasons for this connection? Maybe the extra energetic investment in brain health is only justified when there is an energetic surplus, and doing exercise correlates with having extra energy available? (As opposed to starving and thus needing to conserve energy.) But that doesn't actually make sense, since the extra metabolic expenditure of these processes can't possibly be all that high, and doesn't the brain use almost the same (huge) amount of resources whether it's at rest or very cognitively active?

sliverstorm 10y ago
It's probably not that complicated. It probably goes something like, our species developed using our brains and exercising in harmony, so they wound up linked to eachother, simply because everyone was exercising. The two systems developed together, and simply because there was no reason NOT to be, wound up intertwined. Like what I've heard about automatic transmissions. Supposedly, some automatic transmissions do not lubricate themselves when coasting in neutral (the pump is driven engine-side), and for this reason you shouldn't regularly coast long distances at freeway speeds in neutral on an affected automatic. Why is it this way? Simply because it's easy to slave the pump off the engine-side, and at 65mph, you generally have your engine engaged! So why NOT? Evolution is all about selective pressures, but equally important are the absence of those pressures.
- jey 10y ago
  True, but this does smell an awful lot like a control signal (in the sense of a control system).
drzaiusapelord 10y ago
>but what are some possible evolutionary reasons for this connection? Maybe you should be asking the opposite question like why should evolution reward sedentary life? Human history involves daily exercise in some form that is more strenuous than a long walk and that's clearly connected to our general health and well-being both mentally and physically (why should these be separate to evolution?). What we're doing today is the exception, we shouldn't expect everything to work out as before. I imagine we're in a temporary lull. Either modern society will collapse and we'll go back to farming or hunting and gathering, or we'll invent a exercise pill. There is effort in this direction: http://qz.com/516757/scientists-are-working-on-an-exercise-pill-so-you-never-have-to-work-out-again/ http://qz.com/516757/scientists-are-working-on-an-exercise-p...
- searine 10y ago
  >Maybe you should be asking the opposite question like why should evolution reward sedentary life? If you can live a sedentary lifestyle and still produce children, then evolution doesn't care. In fact, an indoors lifestyle is much more fit in the longterm than a life of hard labor. Evolution isn't trying to create the Platonic Ideal of a human. It just is a thoughtless mechanism to efficiently reproduce DNA.
  - pc86 10y ago
    > If you can live a sedentary lifestyle and still produce children, then evolution doesn't care. Hunter/gatherer humanity did not have the luxury of a sedentary lifestyle, so it did have a negative impact on your ability to produce children for a long time. > In fact, an indoors lifestyle is much more fit in the longterm than a life of hard labor. I think "hard labor" is a bit extreme, but even so, working a physically demanding job is still better for your overall health than a sedentary lifestyle of office job + sitting on the couch watching Netflix.
    - TillE 10y ago
      > better for your overall health Again, evolution does not care. As long as you can survive to about 40 (long enough to raise children), it makes no difference.
      - toasterlovin 10y ago
        Older humans have a lot to contribute to the fitness of their children and grandchildren. Power, resources, labor...
    - deleted 10y ago
      [deleted]
- chrisfosterelli 10y ago
  > Either modern society will collapse and we'll go back to farming or hunting and gathering, or we'll invent a exercise pill. Or maybe people will just learn to exercise regularly and stay healthy? That seems more likely than the collapse of society.
rhondapatrick 10y ago
Interestingly, exercise itself actually helps get an energetically favorable type of energy to the brain in the first place: lactate.[1] Moreover, lactate in the brain triggers the release of BDNF, which causes neurogenesis.[2] I recorded a video conversation with the pioneer of the lactate shuttle theory behind this mechanism which may interest you. https://www.youtube.com/watch?v=lThFQM503EU https://www.youtube.com/watch?v=lThFQM503EU [1] https://en.wikipedia.org/wiki/Lactate_shuttle_hypothesis https://en.wikipedia.org/wiki/Lactate_shuttle_hypothesis [2] http://www.ncbi.nlm.nih.gov/pubmed/21094220 http://www.ncbi.nlm.nih.gov/pubmed/21094220
- StanislavPetrov 10y ago
  Exercise also causes the release of endorphins in the brain that leads to a condition commonly known as "runners high". http://www.runnersworld.com/running-tips/how-to-achieve-a-runners-high http://www.runnersworld.com/running-tips/how-to-achieve-a-ru...
  - bitL 10y ago
    Real runner's high means you started damaging your muscles and brain flushes endorphins to your blood stream in order to keep you being able to continue without experiencing debilitating pain in case you are running from a disaster/predator/death in the last attempt before you cease to be able to move. Not something you'd want to achieve repeatedly.
    - StanislavPetrov 10y ago
      Any exercise can lead to the release of endorphins. Endorphin release doesn't occur only to mask the damage you are doing to yourself in the face of an extreme life threatening situation (which is also accompanied by the release of adrenaline and other hormones). >The endogenous opioids seem likely to be assigned a significant role in the integrated hormonal and metabolic response to exercise. This article reviews the present evidence on exercise and the endogenous opioids, and examines their involvement in a number of widely disparate physiological processes http://www.ncbi.nlm.nih.gov/pubmed/6091217 http://www.ncbi.nlm.nih.gov/pubmed/6091217
searine 10y ago
> but what are some possible evolutionary reasons for this connection? With long term phenotypes like brain health, there probably isn't enough selective pressure to create or maintain this relationship. Rather this result is likely the result of coincidence, and that coincidence was not deleterious enough to be removed by selection. Ex : Exercise stimulates repair enzymes > Excess Repair Enzymes Filter Into Blood Stream > Excess Repair Enzymes Also Fix Brain Cells.
ldehaan 10y ago
your heart is a pump, when you exercise your heart pumps harder and faster, your legs create a flowing motion that helps the blood make it back to the heart. during all this the brain experiences a surge in blood levels, oxygen, metabolic exchanges happen faster and so your brain is more effective. add into that, the body breaks down fats to power you, those fats have omega fatty acids that are released into the blood stream and go to the brain to provide nutrients. this is why drinking coffee wakes you up. what I really want is a pair of those leg pumps that assist the heart, so I can sit on my ass longer and code whilst getting the benefits of exercise on my brain :)
revelation 10y ago
As usual, evolution means there might just be no reason, certainly not one that is reasonable.
- bduerst 10y ago
  I was going to say this as well. Unless it's explicitly linked to surviving natural selection before reproduction, it's more likely that this finding is just a pointless by-product of another biomolecular pathway, even though it may have some discernible benefits. It's like trying to puzzle out why there are nipples on male mammals - it usually devolves to some creative stories and hand waving.
  - omalleyt 10y ago
    Well, male nipples are spandrels https://en.wikipedia.org/wiki/Spandrel_(biology) https://en.wikipedia.org/wiki/Spandrel_(biology) That is, they're useful for the female and not particularly harmful for the male, so they live on. It's also an instance of DRY (don't repeat yourself) "coding" in our DNA: basically males and females carry the same instructions, with a bunch of randomly interspersed if/else conditions that hinge on the presence of testosterone (coded for in the small Y chromosome)
quantumhobbit 10y ago
Prehistoric humans likely exercised as a matter of course. They weren't sedentary. The brain evolved assuming the condition of exercise. naturally occurring byproducts of exercise were just always there for the brain to use.
- seizethecheese 10y ago
  This is my favorite explanation. It may be that the deficiencies of these chemicals are harmful and the release of them returns us to "regular" function, but since we are so sedentary it appears that we are getting a benefit.
  - pizza 10y ago
    Avoiding the teleological default misconception of "evolution means adding features to DNA," to boot.
- searine 10y ago
  You are assuming Hunter/Gatherers expend more energy than modern humans, which is not true (http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0040503 http://journals.plos.org/plosone/article?id=10.1371/journal....) Physical activity levels were also within a standard deviation of one another (between western and h/g populations). The brain evolved in similar conditions to modern man. I would argue current conditions are far better for the brain in terms of good nutrition and low disease. The effect in the OP was not selected for, it is likely a serendipitous biochemical interaction. Repair enzymes from one part of they also effecting another.
  - woodandsteel 10y ago
    As far as calories go, exercise doesn't have much impact. And maybe the Hunter/Gatherers are more efficient in their metabolisms. As far as exercise goes, maybe one standard deviation is enough to produce a brain effect. And maybe there is a lot of variation within modern populations, with many far enough below the average to have a significant effect. I find it really hard to believe that any healthy Hunter/Gatherers sit around all day like so many moderns do.
deleted 10y ago
[deleted]
foxxwinters 10y ago
There's interesting theories behind humans evolving as a distance running (endurance hunting) species, and brain size being required evolutionarily as a tracking mechanism (understanding footprints & getting in the prey's head to understand it's path). The two work in concert because fast prey escapes line of sight and gets mixed up with each other easily, so human endurance becomes much less useful if you can't follow & wear down the appropriate target. "Born to Run" is a fun summary/story about some of this science but there's more hard science out there too if you're interested.
aqwfgm 10y ago
Reason should be some kind of benefit. But honestly, I dont know, here are just some facts. You need to see the connection of systems. Neuromuscular connection of basal ganglia: central part of brain - neural pathway - muscle - and then feeling of movement going back to the brain through hypothalamus and to other areas - from hypothalamus it goes to brain like a shotgun fire. The more you do the same movement the more you fire up the same lines. In order to get faster and more effective movement you add additional channels for signal transport in neuronal connections {this happens through release of BDNF, which induces insertion of new channels, for faster transmission}. This molecule happen to influence formation of memory, survival of neurons and supress your desire to eat. There has been an article from 1998 about reduced cathepsin, which happens to reduce this BDNF. (http://www.ncbi.nlm.nih.gov/pubmed/9514826 http://www.ncbi.nlm.nih.gov/pubmed/9514826) Sooo, again, I dont know, but this seems a bit like a side effect of firing up those circuits, because more or less the same way works memory formation (long-term memory potentiation). I would guess here plays a role effect of neigborhood - niche influencing neurons sitting next to those active pathways. BTW. Also movement should increase your bloodflow, waste created by neurons is now removed much faster, this should go the same for neurotrasmitters - molecules transmitting signal which just flow around and act as signal interference, thus removing part of interference and now you can fire clear signal.
jsprogrammer 10y ago
If you are being active, you probably want to be able to do more. Move easily, see things, predict ahead, etc. When you are not active, you don't need to be doing those things as much.
drawkbox 10y ago
A couple possible reasons: surviving to hunt, fighting/battle and celebration/training/building activities. If you have an elevated heart rate and exercising in the past that might mean going after food where you have to outwit, thus the brain needed to fuel/prepare for that. Additionally, exercise could be fighting, you might also need elevated brain performance during a battle for survival. It might also mean you are doing some work to get a system in place for food and providing that for others in the group. Exercising is probably tied to survival, nourishment and providing. The brain probably has a reward system because it can expend more energy if there is more to be had soon.
- mywittyname 10y ago
  Also, you're probably learning during that time. Think about how young animals play: they practice a lot of the skills they need to survive. It builds dexterity, coordination, reflexes and strength. Evolutionary speaking, those animals whose brains go into "extra learning mode" during exercise likely had a huge advantage over their peers whose brains didn't. Their brains picked up on skills related to hunting and survival and didn't waste energy building neural connections while they're sitting around not doing anything.
  - searine 10y ago
    You two are wildly speculating. The fact is that none of this greatly influences reproductive fitness, so it is unlikely to be acted on by evolution. The effect is likely just biochemical coincidence. Repair enzymes in one part of the body effecting another.
    - nazgul17 10y ago
      I agree that it is speculation, but the evolutionary advantage is pretty clear there: getting extra learning during fights increases your chances of survival in the next fight.
      - searine 10y ago
tn13 10y ago
> The connection between exercise and brain health has now been super conclusively and astonishingly shown, but what are some possible evolutionary reasons for this connection? Both physical activity and brain-health improve survival and a small group of people whose brain became healtheir with physical activity survived at a faster rate than others. Isn't it obvious ? I would assume exercise for early humans did not mean spending 30 minutes running for no reason. They probably spent that time running after a rabbit or running way with someone else's wife on his shoulder etc or tribes that kept well trained armies probably survived at a higher rate than tribes that relied on the Shaman to summon the dead.
ObeyTheGuts 10y ago
To me it is very obvious that physical activity = you are being active and will need more brain power to proccess all the activity, while being inactive means brain power will be energy waste. As only very recently u can do high intellect stuff like computer work while sitting.
stared 10y ago
Neurons evolved from muscles. After exercises muscles needs to be repaired (due to microdamages); it is not unreasonable that there is some positive side-effect for neurons as well.
rsync 10y ago
"The connection between exercise and brain health has now been super conclusively and astonishingly shown, but what are some possible evolutionary reasons for this connection?" Your question assumes that bodily health and brain health are separate and distinct things - as if we are mental beings that just happen to have bodies. Perhaps we should read the headline as "exercise releases body healthy protein" ... I doubt we'd consider that an evolutionary paradox. Probably these results should be considered ipso facto.

by jey 10y ago

sliverstorm 10y ago

It's probably not that complicated. It probably goes something like, our species developed using our brains and exercising in harmony, so they wound up linked to eachother, simply because everyone was exercising. The two systems developed together, and simply because there was no reason NOT to be, wound up intertwined. Like what I've heard about automatic transmissions. Supposedly, some automatic transmissions do not lubricate themselves when coasting in neutral (the pump is driven engine-side), and for this reason you shouldn't regularly coast long distances at freeway speeds in neutral on an affected automatic. Why is it this way? Simply because it's easy to slave the pump off the engine-side, and at 65mph, you generally have your engine engaged! So why NOT? Evolution is all about selective pressures, but equally important are the absence of those pressures.

jey 10y ago
True, but this does smell an awful lot like a control signal (in the sense of a control system).

drzaiusapelord 10y ago

>but what are some possible evolutionary reasons for this connection? Maybe you should be asking the opposite question like why should evolution reward sedentary life? Human history involves daily exercise in some form that is more strenuous than a long walk and that's clearly connected to our general health and well-being both mentally and physically (why should these be separate to evolution?). What we're doing today is the exception, we shouldn't expect everything to work out as before. I imagine we're in a temporary lull. Either modern society will collapse and we'll go back to farming or hunting and gathering, or we'll invent a exercise pill. There is effort in this direction: http://qz.com/516757/scientists-are-working-on-an-exercise-pill-so-you-never-have-to-work-out-again/ http://qz.com/516757/scientists-are-working-on-an-exercise-p...

searine 10y ago
>Maybe you should be asking the opposite question like why should evolution reward sedentary life? If you can live a sedentary lifestyle and still produce children, then evolution doesn't care. In fact, an indoors lifestyle is much more fit in the longterm than a life of hard labor. Evolution isn't trying to create the Platonic Ideal of a human. It just is a thoughtless mechanism to efficiently reproduce DNA.
- pc86 10y ago
  > If you can live a sedentary lifestyle and still produce children, then evolution doesn't care. Hunter/gatherer humanity did not have the luxury of a sedentary lifestyle, so it did have a negative impact on your ability to produce children for a long time. > In fact, an indoors lifestyle is much more fit in the longterm than a life of hard labor. I think "hard labor" is a bit extreme, but even so, working a physically demanding job is still better for your overall health than a sedentary lifestyle of office job + sitting on the couch watching Netflix.
  - TillE 10y ago
    > better for your overall health Again, evolution does not care. As long as you can survive to about 40 (long enough to raise children), it makes no difference.
    - toasterlovin 10y ago
      Older humans have a lot to contribute to the fitness of their children and grandchildren. Power, resources, labor...
  - deleted 10y ago
    [deleted]
chrisfosterelli 10y ago
> Either modern society will collapse and we'll go back to farming or hunting and gathering, or we'll invent a exercise pill. Or maybe people will just learn to exercise regularly and stay healthy? That seems more likely than the collapse of society.

rhondapatrick 10y ago

Interestingly, exercise itself actually helps get an energetically favorable type of energy to the brain in the first place: lactate.[1] Moreover, lactate in the brain triggers the release of BDNF, which causes neurogenesis.[2] I recorded a video conversation with the pioneer of the lactate shuttle theory behind this mechanism which may interest you. https://www.youtube.com/watch?v=lThFQM503EU https://www.youtube.com/watch?v=lThFQM503EU [1] https://en.wikipedia.org/wiki/Lactate_shuttle_hypothesis https://en.wikipedia.org/wiki/Lactate_shuttle_hypothesis [2] http://www.ncbi.nlm.nih.gov/pubmed/21094220 http://www.ncbi.nlm.nih.gov/pubmed/21094220

StanislavPetrov 10y ago
Exercise also causes the release of endorphins in the brain that leads to a condition commonly known as "runners high". http://www.runnersworld.com/running-tips/how-to-achieve-a-runners-high http://www.runnersworld.com/running-tips/how-to-achieve-a-ru...
- bitL 10y ago
  Real runner's high means you started damaging your muscles and brain flushes endorphins to your blood stream in order to keep you being able to continue without experiencing debilitating pain in case you are running from a disaster/predator/death in the last attempt before you cease to be able to move. Not something you'd want to achieve repeatedly.
  - StanislavPetrov 10y ago
    Any exercise can lead to the release of endorphins. Endorphin release doesn't occur only to mask the damage you are doing to yourself in the face of an extreme life threatening situation (which is also accompanied by the release of adrenaline and other hormones). >The endogenous opioids seem likely to be assigned a significant role in the integrated hormonal and metabolic response to exercise. This article reviews the present evidence on exercise and the endogenous opioids, and examines their involvement in a number of widely disparate physiological processes http://www.ncbi.nlm.nih.gov/pubmed/6091217 http://www.ncbi.nlm.nih.gov/pubmed/6091217

searine 10y ago

> but what are some possible evolutionary reasons for this connection? With long term phenotypes like brain health, there probably isn't enough selective pressure to create or maintain this relationship. Rather this result is likely the result of coincidence, and that coincidence was not deleterious enough to be removed by selection. Ex : Exercise stimulates repair enzymes > Excess Repair Enzymes Filter Into Blood Stream > Excess Repair Enzymes Also Fix Brain Cells.

ldehaan 10y ago

your heart is a pump, when you exercise your heart pumps harder and faster, your legs create a flowing motion that helps the blood make it back to the heart. during all this the brain experiences a surge in blood levels, oxygen, metabolic exchanges happen faster and so your brain is more effective. add into that, the body breaks down fats to power you, those fats have omega fatty acids that are released into the blood stream and go to the brain to provide nutrients. this is why drinking coffee wakes you up. what I really want is a pair of those leg pumps that assist the heart, so I can sit on my ass longer and code whilst getting the benefits of exercise on my brain :)

revelation 10y ago

As usual, evolution means there might just be no reason, certainly not one that is reasonable.

bduerst 10y ago
I was going to say this as well. Unless it's explicitly linked to surviving natural selection before reproduction, it's more likely that this finding is just a pointless by-product of another biomolecular pathway, even though it may have some discernible benefits. It's like trying to puzzle out why there are nipples on male mammals - it usually devolves to some creative stories and hand waving.
- omalleyt 10y ago
  Well, male nipples are spandrels https://en.wikipedia.org/wiki/Spandrel_(biology) https://en.wikipedia.org/wiki/Spandrel_(biology) That is, they're useful for the female and not particularly harmful for the male, so they live on. It's also an instance of DRY (don't repeat yourself) "coding" in our DNA: basically males and females carry the same instructions, with a bunch of randomly interspersed if/else conditions that hinge on the presence of testosterone (coded for in the small Y chromosome)

quantumhobbit 10y ago

Prehistoric humans likely exercised as a matter of course. They weren't sedentary. The brain evolved assuming the condition of exercise. naturally occurring byproducts of exercise were just always there for the brain to use.

seizethecheese 10y ago
This is my favorite explanation. It may be that the deficiencies of these chemicals are harmful and the release of them returns us to "regular" function, but since we are so sedentary it appears that we are getting a benefit.
- pizza 10y ago
  Avoiding the teleological default misconception of "evolution means adding features to DNA," to boot.
searine 10y ago
You are assuming Hunter/Gatherers expend more energy than modern humans, which is not true (http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0040503 http://journals.plos.org/plosone/article?id=10.1371/journal....) Physical activity levels were also within a standard deviation of one another (between western and h/g populations). The brain evolved in similar conditions to modern man. I would argue current conditions are far better for the brain in terms of good nutrition and low disease. The effect in the OP was not selected for, it is likely a serendipitous biochemical interaction. Repair enzymes from one part of they also effecting another.
- woodandsteel 10y ago
  As far as calories go, exercise doesn't have much impact. And maybe the Hunter/Gatherers are more efficient in their metabolisms. As far as exercise goes, maybe one standard deviation is enough to produce a brain effect. And maybe there is a lot of variation within modern populations, with many far enough below the average to have a significant effect. I find it really hard to believe that any healthy Hunter/Gatherers sit around all day like so many moderns do.

deleted 10y ago

[deleted]

foxxwinters 10y ago

There's interesting theories behind humans evolving as a distance running (endurance hunting) species, and brain size being required evolutionarily as a tracking mechanism (understanding footprints & getting in the prey's head to understand it's path). The two work in concert because fast prey escapes line of sight and gets mixed up with each other easily, so human endurance becomes much less useful if you can't follow & wear down the appropriate target. "Born to Run" is a fun summary/story about some of this science but there's more hard science out there too if you're interested.

aqwfgm 10y ago

Reason should be some kind of benefit. But honestly, I dont know, here are just some facts. You need to see the connection of systems. Neuromuscular connection of basal ganglia: central part of brain - neural pathway - muscle - and then feeling of movement going back to the brain through hypothalamus and to other areas - from hypothalamus it goes to brain like a shotgun fire. The more you do the same movement the more you fire up the same lines. In order to get faster and more effective movement you add additional channels for signal transport in neuronal connections {this happens through release of BDNF, which induces insertion of new channels, for faster transmission}. This molecule happen to influence formation of memory, survival of neurons and supress your desire to eat. There has been an article from 1998 about reduced cathepsin, which happens to reduce this BDNF. (http://www.ncbi.nlm.nih.gov/pubmed/9514826 http://www.ncbi.nlm.nih.gov/pubmed/9514826) Sooo, again, I dont know, but this seems a bit like a side effect of firing up those circuits, because more or less the same way works memory formation (long-term memory potentiation). I would guess here plays a role effect of neigborhood - niche influencing neurons sitting next to those active pathways. BTW. Also movement should increase your bloodflow, waste created by neurons is now removed much faster, this should go the same for neurotrasmitters - molecules transmitting signal which just flow around and act as signal interference, thus removing part of interference and now you can fire clear signal.

jsprogrammer 10y ago

If you are being active, you probably want to be able to do more. Move easily, see things, predict ahead, etc. When you are not active, you don't need to be doing those things as much.

drawkbox 10y ago

A couple possible reasons: surviving to hunt, fighting/battle and celebration/training/building activities. If you have an elevated heart rate and exercising in the past that might mean going after food where you have to outwit, thus the brain needed to fuel/prepare for that. Additionally, exercise could be fighting, you might also need elevated brain performance during a battle for survival. It might also mean you are doing some work to get a system in place for food and providing that for others in the group. Exercising is probably tied to survival, nourishment and providing. The brain probably has a reward system because it can expend more energy if there is more to be had soon.

mywittyname 10y ago
Also, you're probably learning during that time. Think about how young animals play: they practice a lot of the skills they need to survive. It builds dexterity, coordination, reflexes and strength. Evolutionary speaking, those animals whose brains go into "extra learning mode" during exercise likely had a huge advantage over their peers whose brains didn't. Their brains picked up on skills related to hunting and survival and didn't waste energy building neural connections while they're sitting around not doing anything.
- searine 10y ago
  You two are wildly speculating. The fact is that none of this greatly influences reproductive fitness, so it is unlikely to be acted on by evolution. The effect is likely just biochemical coincidence. Repair enzymes in one part of the body effecting another.
  - nazgul17 10y ago
    I agree that it is speculation, but the evolutionary advantage is pretty clear there: getting extra learning during fights increases your chances of survival in the next fight.
    - searine 10y ago

tn13 10y ago

> The connection between exercise and brain health has now been super conclusively and astonishingly shown, but what are some possible evolutionary reasons for this connection? Both physical activity and brain-health improve survival and a small group of people whose brain became healtheir with physical activity survived at a faster rate than others. Isn't it obvious ? I would assume exercise for early humans did not mean spending 30 minutes running for no reason. They probably spent that time running after a rabbit or running way with someone else's wife on his shoulder etc or tribes that kept well trained armies probably survived at a higher rate than tribes that relied on the Shaman to summon the dead.

ObeyTheGuts 10y ago

To me it is very obvious that physical activity = you are being active and will need more brain power to proccess all the activity, while being inactive means brain power will be energy waste. As only very recently u can do high intellect stuff like computer work while sitting.

stared 10y ago

Neurons evolved from muscles. After exercises muscles needs to be repaired (due to microdamages); it is not unreasonable that there is some positive side-effect for neurons as well.

rsync 10y ago

"The connection between exercise and brain health has now been super conclusively and astonishingly shown, but what are some possible evolutionary reasons for this connection?" Your question assumes that bodily health and brain health are separate and distinct things - as if we are mental beings that just happen to have bodies. Perhaps we should read the headline as "exercise releases body healthy protein" ... I doubt we'd consider that an evolutionary paradox. Probably these results should be considered ipso facto.