I think this study is related to two books I read this summer: Burn, by Herman Pontzer, presents his "constrained energy expenditure hypothesis," and Exercised, by Daniel E. Lieberman, discusses his "costly repair hypothesis."
Together, they try to explain why exercise can force your body to stop using its energy to destroy itself (inflammation, autoimmune diseases) and instead use its energy to restore itself (releasing antioxidants, repairing damage).
Lets agree for the sake of argument that if the body does not have enough energy to do what it needs that causes harm. Then why not eat more food to deal with the problem?
I think this model is missing a critical component: the bodies ability to use energy effectively is limited by having the proper nutrients available. The easiest example being a deficiency of B vitamins since they are used for energy metabolism. Many other factors can impair energy metabolism and just eating more will not fix the situation.
Whereas with this model we have statements that seem too over-simplified:
> The organism’s energy consumption capacity is biologically limited
This seems overstated- we know that certain athletes can consume 2x or even 3x a resting amount to support physical exertion- the human body seems designed to be able to produce more power for physical exertion when needed by consuming more energy (in addition to making long-term adaptations to make energy usage more efficient).
I also think that readers of this paper may take away an understated understanding of the possible negative effects of energy deficiency. Any physiological problem could be impacted by energy metabolism. For example, even if something is known to be caused by a deficiency in a nutrient that cannot be synthesized by the body, it's still possible that improved energy metabolism might be able to reduce the usage of that nutrient in some pathways to conserve more for where it is needed.
- the human body seems designed to be able to produce more power for physical exertion when needed by consuming more energy (in addition to making long-term adaptations to make energy usage more efficient).
Most top athletes are retiring around 35. Their bodies are ruined like those who need to physically work hardly every day. They look elder as well.
We are not machines that will do more when given more sources without consequences.
Most athletes play for reasons other than health. In a competitive environment with physical contact that rewards over-exertion and playing through injuries. Those that keep pushing their body to their limit will likely find consequences. Just doing so many repetitive movements for sports will damage the body unless the athlete can train those pathways to be strong enough. Most athletes seem to play until they can't play through injury anymore.
In contrast, exercise that keeps good health in mind can require noticeable extra energy consumption and seems like it would fall in line with the huge volume of research showing the benefits of exercise.
In contrast this article seems to point to studies of increased resting metabolic rates being harmful with no evidence about exercise.
Well, this should be the main hypothesis of QiGong/TaiChi/Yoga.
The "energy blockages" means the affects of the stress on the body. (tight shoulders, abs etc..) And some mindful streching exercises (like QiGong and Yoga) aims to release this tension on the body (hence the reverse the effect of the stress) and be "healthy"
Agree, with all in full sans the last one. Of course, if you're struggling, seek support.
We all have bad days or even bad weeks, life happens and often it's best to learn this. The current fad (?) of "I'm going to experess my non-positive feelings as they are all the time" gives too much weight to what are normal passing moments.
I don't want to say being a hypochondriac is normalized (else I might get canceled) but... Words, they create worlds. It's important to be mindful of what we choose to create.
Belief drives behavior, and when allowed to perpetuate the victim mentality can cause unnecessary (semi) permanent damage. It's perfectly normal to experience some pain. Don't make more of it than necessary.
So what do you do about stress? How do you recognize it's happening? I found this part informative:
"Stress reactivity occurs specifically in situations that diminish one’s control and where the prospect of being negatively evaluated, rejected, and/or shamed are contextually manipulated (Dickerson et al., 2004)."
I find I get the most stressed when I'm excited about a new challenge -- a new work project, seeing a path to achieving a goal I've been working towards for a while. When I start to feel too excited (or in the framework of this paper, I start to expend too much energy and my heart rate is elevated thinking about all I want to do to overcome the challenge), I can generally reign in the stress by reminding myself that failure happens, my peers will understand it, and I don't have complete control over anything anyway.
Stress most times doesn't reveal itself like that. What you're describing is short term excitement and perhaps anxiety.
Stress is a silent killer. It's basically being mostly unhappy, feeling unfulfilled and trapped. It's a spectrum that can range from simply being unhappy to being deeply depressed.
Lots of interesting stuff about mitochondrial allostatic load. It's essentially a Goldilocks problem - the car that's never driven breaks down quickly when you take it out for a drive, but if you're constantly pushing the accelerator and slamming the brakes, the car's lifetime is cut in half. The paper seems to focus on social and psychological factors that unnecessarily increase stress:
> "From this energetic perspective, the evolution of likes and dislikes, feelings and emotions, and approach/withdrawal behaviors arose to minimize the energetic cost of life."
Case example: Someone just asked me about my holiday season plans and my blood pressure probably went through the roof... I think I'm going to send them this paper.
However moderate exercise (and stress!) stimulates the body to activate trash/repair/rebuild mechanisms which improve health overall.
EDIT:
For example, aerobic exercise stimulates capillary growth lowering pressure required for blood flow.
Periodic, moderate fasting triggers the elimination of accumulated fats which might have toxins built up in them (or have oxidized)
Healthy, emotional stress teaches us to deal with inevitable tragedies.
The body tends to use the same amount of energy regardless of what you do in a day. You can certainly over exercise which causes undue stress on the body. However other than an adaptive period at the start of regular exercise your body adapts to the increased caloric use from exercise by down regulating other processes to conserve energy. Typically an excess of calories is used by production of lipid fluid in adipose tissue and over expression of global inflammation. Once you begin exercising regularly the body generally stops using stored lipids for extra energy to compensate for the exercise and instead down regulates inefficient and generally harmful processes like random global inflammation.
As mentioned the Goldilocks zones are where you’re not forcing the body beyond what it can safely allocate to exercise in a day without causing stress in other processes. Generally though that Goldilocks zone is significantly greater than most people do in exercise in a week, but would typically fall in the zone of “moderate” exercise from a clinical point of view. This is effectively 3-6 times the expenditure of energy from rest for 150 minutes per week spread over a week for at least 10 minutes of moderately strenuous exercise at 70% heart rate per session. Most people in their 40’s or 50’s would typically find this fairly grueling, but that’s because of that homeostatic adaptation - the body resists changing its homeostasis and induces all sorts of negative experiences during the adaptation phase. Once you’ve adapted the opposite feelings present for the same reason - you begin to crave a routine of exercise because you body resists the adaptation to a more sedentary life.
N.b., This is why while exercise definitely helps lose weight, it’s primarily by managing inflammation and mood. This is why the only significant way you can lose weight over time is to reduce caloric intake materially under your homeostatic energy consumption.
I'm not saying that to be snarky. Just as an FYI that it can be kinda hard to even describe how one came across this knowledge. Like asking someone how they know LC circuits act as a resonator.
And I guess exercise science is even less popular than physics. You can find the latter on Wikipedia, and a bit of the former too:
I had a somewhat similar question about exercise vs physically demanding work, since the former helps to have a healthy heart and the latter seems to do the opposite. Explanations I've found were tied to the average daily heart rate. Exercises are intense but it's only a few hours per week, and over time they tend to lower the average heart rate. Physical work is typically less straining but it takes a big portion of the week and as the result increases the average heart rate.
I guess the problem of exercise (intense but short) vs chronic stress (moderate but 24x7) could have a similar explanation.
I would be willing to bet that there are just confounding factors. People who do physical work differ from people who do not in so many ways that it would be impossible to do any sort of controlled study.
I don’t think the claim is that it just uses energy, it’s that it uses energy to the detriment of other processes.
The body is extraordinarily complex, so I don’t think you can extrapolate that to anything else that uses energy.
Any garden variety gym rat will tell you that when you worked out you eat a lot more. And that may be the same for stress, but perhaps what your body does with the energy when you exercise is different.
Exercise modulates hunger (generally, cardio increases perceived hunger while resistance training actually blunts it for a time). But people putting in work at the gym are already in a health conscious mindset and will apply that to their food choices, even if they aren't on an explicit diet plan. If you just left a gallon of sweat on the treadmill you're probably not gonna buy a pizza or McDonald's burger in the way home. It just feels like an obvious step backwards in the moment.
Meanwhile, being in a stressed state that reduces executive function is going to lead people to the quick, easy, hyper palatable, high energy density, unhealthy food options available.
I wouldn't be so sure. The brain is responsible for about 20% of resting metabolic rate, which translates to 300-350 calories per day for the average person.
300 calories is about the same as 30 minutes of zone 3 cardio (70-80% max heart rate, i.e. pretty high perceived exertion).
Most people in an exercise routine would only do that a couple times per week.
An "overactive" brain, day in day out, could add up to more than most people deliberately exercise.
it sounds like the authors are suggesting that additional energy usage caused by stress can, in isolation from other causes, be a mechanism for disease. But that doesn’t make much sense:
- our metabolisms are adaptable, so why wouldn’t this increase in energy use simply be offset by an increase in energy production? It can’t be that people who are stressed in general aren’t getting enough energy, because that would correlate stress with weight loss, but I would argue that there are plenty of overweight people with stress.
- if the argument is that an increased metabolism by itself is the culprit, then why wouldn’t people with higher metabolisms in general — like anyone who exercises regularly, but certainly athletes — not also experience more disease? If your answer is “that’s different for some reason”, then that means that increased energy usage and metabolism is not by itself the cause, which suggests it may not be the cause at all.
Furthermore, even granting the supposition that stress requires increased energy usage, their abstract doesn’t make much sense:
- “Living organisms have a limited capacity to consume energy.” Okay, so that means that no matter how stressed we get, there’s a cap to the energy we can use. But how is that relevant, since it also applies to exercise or other energy utilization by the body? Why does a limited capacity to consume energy only apply to stress?
- “Overconsumption of energy by [stress handling] brain-body processes leads to … excess energy expenditure above the organism’s optimum”. Thats basically a tautology, but more importantly, it doesn’t tell us that energy consumption above “optimal” — which seems extremely vague — is a bad thing.
- “In turn, [excess energy consumption above the optimal] accelerates physiological decline in cells, laboratory animals, and humans, and may drive biological aging”. So that “may” is a pretty good reason to dismiss this, since again why wouldn’t this lead to increased disease among athletes or anyone with higher metabolism?
- “Mechanistically, the energetic restriction of growth, maintenance and repair processes leads to the progressive wear-and-tear of molecular and organ systems” Maybe, but why are they energetically restricted if metabolism has increased to provide more energy? And again, why don’t we then see increased disease and aging in anyone who exercises regularly, since that exercise not only uses energy that restricts growth, maintenance and repair, but exercise causes more need for repair.
I think the core problem is that it’s all going to boil down to how you define “optimum”, which the authors conveniently don’t. The authors are going to be left with defining “optimum” as meaning “that energy usage which does not cause disease”. But that’s no different than simply claiming “stress causes disease”, so this model describes nothing, since it tells us nothing about how to identify non-optimum energy usage or how non-optimum energy usage causes disease.
Humans have a massive capacity to vary energy use. Highly trained endurance athletes like professional road cyclists and triathletes can average 3x or more the typical daily energy expenditure of a non-athlete on a long term basis. The idea that psychological stress can overwhelm the body's ability to produce energy does not seem credible to me.
Those people have trained very deliberately over years to reach that level of performance, on top of an innate genetic disposition.
Undoubtedly, in absolute terms they have a higher capacity to withstand the negative physical effects of psychosocial stress as described in the paper, precisely because of these physiological adaptations.
If regular people trained themselves to deal with stress then they would have a higher capacity too.
The paper is referring to the maximum capacity of a particular organism at a particular moment in time. It doesn't assert that the capacity is uniform across a species or doesn't change over time.
>Okay, so that means that no matter how stressed we get, there’s a cap to the energy we can use. But how is that relevant, since it also applies to exercise or other energy utilization by the body? Why does a limited capacity to consume energy only apply to stress?
It doesn't. That limited capacity to consume energy applies to exercise, brain activity, thermogenesis, digestion, and every other biological process as well. It is a fundamental aspect of cellular biology and a major focus in the field of exercise physiology.
Fitness training is the very slow and deliberate process of pushing these limits tiny percentages higher.
I suggest you build some practical and theoretical knowledge of the field before dismissing the paper.
It is about a biological/physiological model based on energy consumption when stressed, not the machine learning energy-based models championed by Yann LeCunn.
This paper reminds me of the “insight” / factoid that all mammals are basically born with the same rough number of heartbeats, and then they die. Smaller animals like mice have shorter lifespans and faster heartbeats. Larger ones like whales and elephants have slower heartbeats and longer lives.
The humorous (and obviously false, though apparently not if this paper is out there) corollary is that any exercise and non-sedentary lifestyle means you lose years of your life
This is the battery “theory,” and is obviously untrue from all evidence collected. Exercise and specifically improvement of VO2max, which is the bodies ability to pump and process a volume of blood and oxygen in a period of time, are some of the strongest predictors of life and health span. A lack of exercise also transpires to significantly increase global inflammation in the body - in fact regular exercise forces the body to adapt to a new homeostatic use of calories away from random inflammation to conserve daily caloric expenditure towards that exercise. There’s no evidence to support the battery “theory,” despite certain anti science politicians popularizing it.
OG study that found a roughly same number of heartbeats was only concerned with averages - https://pubmed.ncbi.nlm.nih.gov/9316546/ . Interestingly humans are outliers with 2-3x the expected number of heartbeats. The way the data was presented always gave me a strong "everything looks linear when plotted on a log scale with big marker" vibe... however it could be totally possible that there is some correlation there.
Maybe evolutionary, there is optimal amount of time for organisms to survive relative to their size. Organism size, in turn, correlates with heart size and heart size correlates with how fast it beats. Probably totally missing the mark, but if it was true, it would be interesting to look into why there are outliers.
Anywho, I find it humorous to think about a battery theory car analogy - "every car has a preset number of miles and maintenance would decrease usable lifespan of the car because you need to drive to the mechanic".
> This is the battery “theory,” and is obviously untrue from all evidence collected. Exercise and specifically improvement of VO2max, which is the bodies ability to pump and process a volume of blood and oxygen in a period of time, are some of the strongest predictors of life and health span.
Exercise and specifically improvement of VO2max also decrease your average heart rate, so it's quite aligned with the battery theory.
Haven't done the math but maybe they aren't so disconnected. If I can trade off an elevated heart rate of 170 for an hour every day or two in exchange for dropping my resting heartbeat from 70 to 50, I should end up with more years to use those finite heartbeats. As with most things in life it's about balance. Extremes and absolutes in most everything tend to result in poor outcomes. You don't want to be sitting 24/7 or running 24/7.
+120 bpm for 60min = -7200 beats off your life
-20 bpm for 23 hours = +27600 beats added to your life
Net: +20400 beats, or 6.8 hrs added, every day you keep it up
Obviously some factors missing in that, you can't live forever.. but back of the envelope it nets positive not negative
I think this study is related to two books I read this summer: Burn, by Herman Pontzer, presents his "constrained energy expenditure hypothesis," and Exercised, by Daniel E. Lieberman, discusses his "costly repair hypothesis."
Together, they try to explain why exercise can force your body to stop using its energy to destroy itself (inflammation, autoimmune diseases) and instead use its energy to restore itself (releasing antioxidants, repairing damage).
Kurtzgesagt had a video about this very recently too. About calory expenditure.
This one: https://youtu.be/vSSkDos2hzo
When I search (amazon, google, and other searches) for one these books, the other also shows up as a very close result. And vice versa as well.
Lets agree for the sake of argument that if the body does not have enough energy to do what it needs that causes harm. Then why not eat more food to deal with the problem?
I think this model is missing a critical component: the bodies ability to use energy effectively is limited by having the proper nutrients available. The easiest example being a deficiency of B vitamins since they are used for energy metabolism. Many other factors can impair energy metabolism and just eating more will not fix the situation.
Whereas with this model we have statements that seem too over-simplified:
> The organism’s energy consumption capacity is biologically limited
This seems overstated- we know that certain athletes can consume 2x or even 3x a resting amount to support physical exertion- the human body seems designed to be able to produce more power for physical exertion when needed by consuming more energy (in addition to making long-term adaptations to make energy usage more efficient).
I also think that readers of this paper may take away an understated understanding of the possible negative effects of energy deficiency. Any physiological problem could be impacted by energy metabolism. For example, even if something is known to be caused by a deficiency in a nutrient that cannot be synthesized by the body, it's still possible that improved energy metabolism might be able to reduce the usage of that nutrient in some pathways to conserve more for where it is needed.
- the human body seems designed to be able to produce more power for physical exertion when needed by consuming more energy (in addition to making long-term adaptations to make energy usage more efficient).
Most top athletes are retiring around 35. Their bodies are ruined like those who need to physically work hardly every day. They look elder as well.
We are not machines that will do more when given more sources without consequences.
> ...retiring around 35. Their bodies are ruined
From what I can find, this is incorrect, unless the athlete is doing a high impact sport like American football, rugby, boxing etc.
If they're doing a non impact sport like swimming, cycling, running, they are likely to live longer and healthier than non athletes.
https://healthland.time.com/2012/12/14/fast-stronger-longer-...
https://pmc.ncbi.nlm.nih.gov/articles/PMC4534511/
Most athletes play for reasons other than health. In a competitive environment with physical contact that rewards over-exertion and playing through injuries. Those that keep pushing their body to their limit will likely find consequences. Just doing so many repetitive movements for sports will damage the body unless the athlete can train those pathways to be strong enough. Most athletes seem to play until they can't play through injury anymore.
In contrast, exercise that keeps good health in mind can require noticeable extra energy consumption and seems like it would fall in line with the huge volume of research showing the benefits of exercise.
In contrast this article seems to point to studies of increased resting metabolic rates being harmful with no evidence about exercise.
Well, this should be the main hypothesis of QiGong/TaiChi/Yoga.
The "energy blockages" means the affects of the stress on the body. (tight shoulders, abs etc..) And some mindful streching exercises (like QiGong and Yoga) aims to release this tension on the body (hence the reverse the effect of the stress) and be "healthy"
Stress management isn't just about understanding the problem—it's about actionable solutions.
Exercise, even a brief walk, reduces cortisol and boosts mood-enhancing endorphins.
Meditation and mindfulness, once seen as trendy, are now scientifically proven to rewire the brain for better stress handling.
Nutrition plays a surprising role; omega-3-rich foods like salmon can lower stress hormones.
Quality sleep, especially deep sleep, allows the brain to reset and repair.
Finally, don't underestimate the power of social support. Sharing your struggles with others can significantly lighten your mental load.
Agree, with all in full sans the last one. Of course, if you're struggling, seek support.
We all have bad days or even bad weeks, life happens and often it's best to learn this. The current fad (?) of "I'm going to experess my non-positive feelings as they are all the time" gives too much weight to what are normal passing moments.
I don't want to say being a hypochondriac is normalized (else I might get canceled) but... Words, they create worlds. It's important to be mindful of what we choose to create.
Belief drives behavior, and when allowed to perpetuate the victim mentality can cause unnecessary (semi) permanent damage. It's perfectly normal to experience some pain. Don't make more of it than necessary.
So what do you do about stress? How do you recognize it's happening? I found this part informative:
"Stress reactivity occurs specifically in situations that diminish one’s control and where the prospect of being negatively evaluated, rejected, and/or shamed are contextually manipulated (Dickerson et al., 2004)."
I find I get the most stressed when I'm excited about a new challenge -- a new work project, seeing a path to achieving a goal I've been working towards for a while. When I start to feel too excited (or in the framework of this paper, I start to expend too much energy and my heart rate is elevated thinking about all I want to do to overcome the challenge), I can generally reign in the stress by reminding myself that failure happens, my peers will understand it, and I don't have complete control over anything anyway.
Stress most times doesn't reveal itself like that. What you're describing is short term excitement and perhaps anxiety.
Stress is a silent killer. It's basically being mostly unhappy, feeling unfulfilled and trapped. It's a spectrum that can range from simply being unhappy to being deeply depressed.
So the upshot is that your body is using its energy to deal with stress rather than other problems?
doesn't matter what model you use to explain it.
cortisol.
too much of it or too regularly opens the door to many diseases.
Are there any proxy markers we can use to model cortisol, right now? Like HRV or simply continuous heart rate monitoring?
Link to full paper:
https://www.picardlab.org/uploads/7/7/8/4/77845210/2022_bobb...
Lots of interesting stuff about mitochondrial allostatic load. It's essentially a Goldilocks problem - the car that's never driven breaks down quickly when you take it out for a drive, but if you're constantly pushing the accelerator and slamming the brakes, the car's lifetime is cut in half. The paper seems to focus on social and psychological factors that unnecessarily increase stress:
> "From this energetic perspective, the evolution of likes and dislikes, feelings and emotions, and approach/withdrawal behaviors arose to minimize the energetic cost of life."
Case example: Someone just asked me about my holiday season plans and my blood pressure probably went through the roof... I think I'm going to send them this paper.
Diseases like chronic fatigue syndrome are thought to be the result of mitochondrial dysfunction, right? Maybe that also fits in here.
Does it mean exercising regularly does the same?
My understanding is yes.
However moderate exercise (and stress!) stimulates the body to activate trash/repair/rebuild mechanisms which improve health overall.
EDIT:
For example, aerobic exercise stimulates capillary growth lowering pressure required for blood flow. Periodic, moderate fasting triggers the elimination of accumulated fats which might have toxins built up in them (or have oxidized) Healthy, emotional stress teaches us to deal with inevitable tragedies.
Exercise seems to stimulate the mechanisms it’s claiming stress depresses, so probably no.
But exercise does use lots of energy. Probably more than stress.
The body tends to use the same amount of energy regardless of what you do in a day. You can certainly over exercise which causes undue stress on the body. However other than an adaptive period at the start of regular exercise your body adapts to the increased caloric use from exercise by down regulating other processes to conserve energy. Typically an excess of calories is used by production of lipid fluid in adipose tissue and over expression of global inflammation. Once you begin exercising regularly the body generally stops using stored lipids for extra energy to compensate for the exercise and instead down regulates inefficient and generally harmful processes like random global inflammation.
As mentioned the Goldilocks zones are where you’re not forcing the body beyond what it can safely allocate to exercise in a day without causing stress in other processes. Generally though that Goldilocks zone is significantly greater than most people do in exercise in a week, but would typically fall in the zone of “moderate” exercise from a clinical point of view. This is effectively 3-6 times the expenditure of energy from rest for 150 minutes per week spread over a week for at least 10 minutes of moderately strenuous exercise at 70% heart rate per session. Most people in their 40’s or 50’s would typically find this fairly grueling, but that’s because of that homeostatic adaptation - the body resists changing its homeostasis and induces all sorts of negative experiences during the adaptation phase. Once you’ve adapted the opposite feelings present for the same reason - you begin to crave a routine of exercise because you body resists the adaptation to a more sedentary life.
N.b., This is why while exercise definitely helps lose weight, it’s primarily by managing inflammation and mood. This is why the only significant way you can lose weight over time is to reduce caloric intake materially under your homeostatic energy consumption.
How did you come by this information and do you have any sources / further reading on this?
Kurzgesagt – In a Nutshell : We Need to Rethink Exercise (Updated Version) - https://www.youtube.com/watch?v=vSSkDos2hzo
Their videos have a section where they link the sources. In this case https://sites.google.com/view/sources-workoutparadox
This is basically exercise physiology 101.
I'm not saying that to be snarky. Just as an FYI that it can be kinda hard to even describe how one came across this knowledge. Like asking someone how they know LC circuits act as a resonator.
And I guess exercise science is even less popular than physics. You can find the latter on Wikipedia, and a bit of the former too:
https://en.m.wikipedia.org/wiki/Exercise_physiology
There is a lot of great YouTube content about exercise physiology too, if you can cut through the "bro science" ecosystem.
[dead]
I had a somewhat similar question about exercise vs physically demanding work, since the former helps to have a healthy heart and the latter seems to do the opposite. Explanations I've found were tied to the average daily heart rate. Exercises are intense but it's only a few hours per week, and over time they tend to lower the average heart rate. Physical work is typically less straining but it takes a big portion of the week and as the result increases the average heart rate.
I guess the problem of exercise (intense but short) vs chronic stress (moderate but 24x7) could have a similar explanation.
I would be willing to bet that there are just confounding factors. People who do physical work differ from people who do not in so many ways that it would be impossible to do any sort of controlled study.
I don’t think the claim is that it just uses energy, it’s that it uses energy to the detriment of other processes.
The body is extraordinarily complex, so I don’t think you can extrapolate that to anything else that uses energy.
Any garden variety gym rat will tell you that when you worked out you eat a lot more. And that may be the same for stress, but perhaps what your body does with the energy when you exercise is different.
Exercise modulates hunger (generally, cardio increases perceived hunger while resistance training actually blunts it for a time). But people putting in work at the gym are already in a health conscious mindset and will apply that to their food choices, even if they aren't on an explicit diet plan. If you just left a gallon of sweat on the treadmill you're probably not gonna buy a pizza or McDonald's burger in the way home. It just feels like an obvious step backwards in the moment.
Meanwhile, being in a stressed state that reduces executive function is going to lead people to the quick, easy, hyper palatable, high energy density, unhealthy food options available.
I wouldn't be so sure. The brain is responsible for about 20% of resting metabolic rate, which translates to 300-350 calories per day for the average person.
300 calories is about the same as 30 minutes of zone 3 cardio (70-80% max heart rate, i.e. pretty high perceived exertion).
Most people in an exercise routine would only do that a couple times per week.
An "overactive" brain, day in day out, could add up to more than most people deliberately exercise.
it sounds like the authors are suggesting that additional energy usage caused by stress can, in isolation from other causes, be a mechanism for disease. But that doesn’t make much sense:
Furthermore, even granting the supposition that stress requires increased energy usage, their abstract doesn’t make much sense: I think the core problem is that it’s all going to boil down to how you define “optimum”, which the authors conveniently don’t. The authors are going to be left with defining “optimum” as meaning “that energy usage which does not cause disease”. But that’s no different than simply claiming “stress causes disease”, so this model describes nothing, since it tells us nothing about how to identify non-optimum energy usage or how non-optimum energy usage causes disease.Humans have a massive capacity to vary energy use. Highly trained endurance athletes like professional road cyclists and triathletes can average 3x or more the typical daily energy expenditure of a non-athlete on a long term basis. The idea that psychological stress can overwhelm the body's ability to produce energy does not seem credible to me.
Those people have trained very deliberately over years to reach that level of performance, on top of an innate genetic disposition.
Undoubtedly, in absolute terms they have a higher capacity to withstand the negative physical effects of psychosocial stress as described in the paper, precisely because of these physiological adaptations.
If regular people trained themselves to deal with stress then they would have a higher capacity too.
The paper is referring to the maximum capacity of a particular organism at a particular moment in time. It doesn't assert that the capacity is uniform across a species or doesn't change over time.
>Okay, so that means that no matter how stressed we get, there’s a cap to the energy we can use. But how is that relevant, since it also applies to exercise or other energy utilization by the body? Why does a limited capacity to consume energy only apply to stress?
It doesn't. That limited capacity to consume energy applies to exercise, brain activity, thermogenesis, digestion, and every other biological process as well. It is a fundamental aspect of cellular biology and a major focus in the field of exercise physiology.
Fitness training is the very slow and deliberate process of pushing these limits tiny percentages higher.
I suggest you build some practical and theoretical knowledge of the field before dismissing the paper.
[dead]
It is about a biological/physiological model based on energy consumption when stressed, not the machine learning energy-based models championed by Yann LeCunn.
This paper reminds me of the “insight” / factoid that all mammals are basically born with the same rough number of heartbeats, and then they die. Smaller animals like mice have shorter lifespans and faster heartbeats. Larger ones like whales and elephants have slower heartbeats and longer lives.
The humorous (and obviously false, though apparently not if this paper is out there) corollary is that any exercise and non-sedentary lifestyle means you lose years of your life
This is the battery “theory,” and is obviously untrue from all evidence collected. Exercise and specifically improvement of VO2max, which is the bodies ability to pump and process a volume of blood and oxygen in a period of time, are some of the strongest predictors of life and health span. A lack of exercise also transpires to significantly increase global inflammation in the body - in fact regular exercise forces the body to adapt to a new homeostatic use of calories away from random inflammation to conserve daily caloric expenditure towards that exercise. There’s no evidence to support the battery “theory,” despite certain anti science politicians popularizing it.
OG study that found a roughly same number of heartbeats was only concerned with averages - https://pubmed.ncbi.nlm.nih.gov/9316546/ . Interestingly humans are outliers with 2-3x the expected number of heartbeats. The way the data was presented always gave me a strong "everything looks linear when plotted on a log scale with big marker" vibe... however it could be totally possible that there is some correlation there.
Maybe evolutionary, there is optimal amount of time for organisms to survive relative to their size. Organism size, in turn, correlates with heart size and heart size correlates with how fast it beats. Probably totally missing the mark, but if it was true, it would be interesting to look into why there are outliers.
Anywho, I find it humorous to think about a battery theory car analogy - "every car has a preset number of miles and maintenance would decrease usable lifespan of the car because you need to drive to the mechanic".
> This is the battery “theory,” and is obviously untrue from all evidence collected. Exercise and specifically improvement of VO2max, which is the bodies ability to pump and process a volume of blood and oxygen in a period of time, are some of the strongest predictors of life and health span.
Exercise and specifically improvement of VO2max also decrease your average heart rate, so it's quite aligned with the battery theory.
Haven't done the math but maybe they aren't so disconnected. If I can trade off an elevated heart rate of 170 for an hour every day or two in exchange for dropping my resting heartbeat from 70 to 50, I should end up with more years to use those finite heartbeats. As with most things in life it's about balance. Extremes and absolutes in most everything tend to result in poor outcomes. You don't want to be sitting 24/7 or running 24/7.
Starting with 60 RHR:
+120 bpm for 60min = -7200 beats off your life -20 bpm for 23 hours = +27600 beats added to your life Net: +20400 beats, or 6.8 hrs added, every day you keep it up
Obviously some factors missing in that, you can't live forever.. but back of the envelope it nets positive not negative
Naked mole rats live over 30 years, because they have additional copies of a gene known to protect against DNA damage.
I think the theory is that exercise has many other benefits that make up for the increased energy usage.
Do the people downvoting my comment think I believe in this theory, or is there another reason?
“Factoid” means untrue by definition. I thought it an interesting novelty
Down voting on HN on HN seems to be a sign of "this idea breaks the model I have in my head, and my biases tell me I can't be mistaken."