The Benefits of Exercise as the Results of Hormesis
Exercise modestly slows aging. In humans epidemiological data only allows for the establishment of correlation between physical activity and measures of aging and mortality. Animal data, however, shows that regular exercise modestly slows aging to an extent that improves long-term health, increasing healthspan without extending maximum life span. It is not as impressive as the effects of calorie restriction on life span, but the effects on health along the way are not all that dissimilar in nature.
In today's open access paper, the authors present a view of exercise and aging that is essentially hormetic in nature. They suggest that exercise slows aging because the short-term stresses generated by exercise overlap to some degree with the long-term stresses generated by the aging of tissues, and adaptation to the former grants greater resistance to the latter. This really need not be the case for exercise to slow aging, however. All that is needed is for the stresses of exercise to trigger generally beneficial responses. Or for exercise to correlate with reduced visceral fat burden, or reduced frailty, or reduced overall calorie intake.
Hormesis is used to describe situations in which mild stress and damage can produce a net gain in function by spurring a lasting increase in maintenance, repair, and defensive activities among the cells making up our tissues. Many forms of stress have this effect, such as reduced nutrient intake, exposure to toxins, heat, cold, and so forth. Exercise evidently stresses tissues via increased energy demands and pushes mitochondria to greater activity, generating oxidative stress as a side-effect, which cells must respond to with greater maintenance, but it also produces a range of other stress mechanisms, such as via inflammatory signaling.
Preventive lifestyle strategies such as exercise have emerged as potent, cost-effective means of reducing chronic disease risk. Exercise has a critical role in disease prevention and has been proposed as a form of "medicine". The protective effects of exercise on chronic disease risk are ultimately accumulated over time through physiological adaptations to the stress of exercise. Acute exercise causes widespread physiological disruptions that require a complex, integrated response from the major physiological systems (autonomic, cardiovascular, metabolic, musculoskeletal, etc.) to meet the substantial requirements of human locomotion. Repeated exposure to the physiological disruptions incurred by acute exercise (through exercise training) stimulate physiological adaptations that act to attenuate stress during subsequent exercise bouts. These exercise adaptations provide the foundation through which individuals can adapt and improve their ability to perform physical work (e.g., increase muscular power, endurance, aerobic capacity, etc.) and also prevent development of age-related chronic disease.
Thus, physiologic adaptations to exercise are the latent mechanisms through which exercise acts as medicine and reduces chronic disease risk. Despite seminal work that has identified several key mechanisms underlying the protective effects of exercise, there has yet to be an overarching hypothesis that explains broadly why or how it is that exercise protects against age-related chronic disease. We posit that exercise prevents age-related chronic disease because it acutely elicits physiological responses that mimic physiological changes seen with aging, the greatest contributing risk factor to all chronic disease. Thus, we propose the hypothesis that exercise is "medicine" that protects against age-related chronic diseases because exercise can effectively simulate "aging."
Acute exercise transiently disrupts cardiovascular, musculoskeletal, and brain function and triggers a substantial inflammatory response in a manner that mimics aging/age-related chronic disease. Data indicate that select acute exercise responses may be similar in magnitude to changes seen with an added 10-50 years of aging. The initial insult of the age-mimicking effects of exercise induces beneficial adaptations that serve to attenuate disruption to successive "aging" stimuli (i.e., exercise). Ultimately, these exercise-induced adaptations reduce the subsequent physiological stress incurred from aging and protect against age-related chronic disease. To further examine this hypothesis, future work should more intricately describe the physiological signature of different types/intensities of acute exercise in order to better predict the subsequent adaptation and chronic disease prevention with exercise training in healthy and at-risk populations.
Execrise is good for you?!?!?! how novel!
Maybe we should spend another billion to confirm (sarcasm)
A nice discussion of mechanisms for how health is maintained (improved?) through thoughtful exercise (frequency, duration, variation, focus, etc.)
And, it is reasonable to posit that it: "... improves long-term health, increasing healthspan without extending maximum life span.."
but why not maximum life span?
Further: Why can we not run as fast, lift as much, act as accurately/ skillfully, etc., in our sports from teens, to twenties, to thirties, and beyond... typically peaking at a predictable age? though we have the same exposure to world-class coaches, trainers, health professionals, etc., especially within elite sports where continuing an athlete's career is well funded and much sought after? (though many long-distance, endurance-based activities continue well into middle age at a world class level). Have the 'peak' ages in sports increased over the generations with technology and knowledge? - even those with little external damage from the activity such as swimming.
Herein is an excellent line of research into the body's lack of regeneration, ineffective ability to recover and optimize with time, and focussed deterioration, with lifestyles otherwise being very consistent and measured in an athletes life. Extend an athlete's peak performance and perhaps realize those interventions which may extend a human body beyond its current 'service life'. My 2c.
Mike:
Query whether being at Peak performance is good for longevity. The centenarian list of well known sports people is not all that long in relation to total centenarians. Such a list is on wikipedia. Many centenarians likely never reach peak physical performance with many of them doing nothing more strenuous than walking or gardening for the majority of their physical activity. Peak performance may not extend longevity and may even be detrimental to longevity.
https://en.wikipedia.org/wiki/List_of_centenarians_(sportspeople)
Exercise can be "beneficial" in moderation, but too much exercise, or exercise when one has an illness or disability can be harmful. Too much exercise can kill prematurely and there fore shorten one's life.
Exercise has both beneficial and harmful effects. In moderation the "beneficial" can be greater than "the harmful".
Get a doctor's check up before starting vigorous exercise.
I suspect the diminishing returns from exercise concerning lifespan, for us, now, are simply that most chronic disease results from how far we have diverged from how evolution shaped us. We aren't 'made' to be sedentary, eat all the time, eat processed crap, fill ourselves up with booze and other drugs etc etc. Exercise simply helps to defeat lifestyle damage.
Hi there!
Hi Jer, just a 2 cents; exercise only increases healthspan/average lifespan because maximum lifespan is mostly independent from what happens 'in the middle'...avg/healthspan. That is not to say you don't need good health to reach the maximum; it's just a secondary thing. I.e. you need to maintain a certain threshold to 'reach the maximum'...or else, you don't even reach it -- you die prematurely 'before you time'..or should I say 'before your maximum/maximal time'.
We can reach the maximum...or not. And die 'in between'..which is the average/healthspan.
Many many people will not reach the maximum possible for human's specie; which is roughly 122 (125-130); as the most most most 'max', a pretty hard limit; we hope it's soft (limit) but it'S a quite Hard limit for humans. It's been shown in your Very Telomeres...we just don't have 'enough left' to even Go Beyond 130 or so...(especially in our immune cells which, by 115-120 years old; are nearly fully depleted in telomeric DNA...hence...life cannot continue because 'lacking DNA/running out of DNA'...if we 'lose at the current speed' -- speed of loss is Major Determinant) or should I say, running out of Synthesized DNA -- that overcomes the 'loss' we incur each day; it's a balance Synthesis vs Loss. With age the balance tips towards the latter; and the former reduces or tops. In effect - an Unbalance happens, and you lose more than you gain. That's what we call 'net negative/net loss' (instead of net gain). And, also, dysfunctioning Repair; DNA Repair is Extremely Important of why we live 120...without DNA Repair (Helicase, Excision Repair, NHEJ..BER/NER); we woud never reach more than 30-40...because too DNA Damage (as permanent/left unrepaired) -> hastened death).
I mean, our whole life, is, technically, a 'net loss'...there is no real gain at any point...rather, there is 'slowing the losing' --- slowing the hemorrhaging...(in hemorrhaging word.. there is AGING word; 'hemorrhAging'; that's what happens...you bleed (fig.) and you age (phys.).
If you slow down the 'net loss'...well, you're losing Less and Slower...that's trying to 'save the kitchen utensils, plates, kitchenware.....'save things' (from disappearing forever)''. In other words, 'save yourself'...which equals 'conserve yourself' and 'slow down the loss'..and you will live longer. It's same with a Candle...when you burn the candle too quick...your candle is gone quick.
''Burning the Candle By Both Ends''. That's Overdoing it and 'living Fast' --> Aging Fast -->
Live Fast, Die Young.
When you live slower (not in the fast (left) lane, but the slow 'right' lane), you just lose slower and less --over longer period of time.
Maximum lifespan is 100% the DNA Domain ---- Telomeres, Methylome, Histome, Telosome, Nucleosome, Chromosome, Genes-osome, Epigenetic Clock-osome, Mitochondrosome, Inflammasome, Lysosome, Spliceosome, Extra-cellularosome, Cytosome, etc...in other words; your DNA-o-zomes...just like the O-zone. Well, these (o) zones...and somes...determine your Max life, as human.
Exercise, boots your average/healthspan...because you keep healthy...but it does not stopp At All the 'aging process' from continuing its course --unabated. Or, let's ...'very slightly abated'. but so little..it's not even worth mentionning...i.e. you continue aging...exercise or not.
Exercise Does slow down the accumulation of defects with age, and helps you to keep that younger threshold and younger composure...like..keeping your muscle mass (important muscles have a control on your skeletal moving capacity...but also on your blood glucose (besides the pancreas); for muscle cells can improve diabetes/insulin resistance via increased insulin sensitivity and whole body glucose disposal -- better/more insulin/functioning...better job reducing blood glucose 'spikes' in tandem with beta-cells in your pancreas making insulin; and Reduced Insuling Signaling -- IGF/Insulin Growth Factor -- excess mTOR activation -- excess premature senescence signaling (via geronconversion by mTOR); means spontaneous senescence (cell cycle exit)));
But, that, does not stop anythng in the 'DNA domain'...which is Where 'it happens'...the Breaking. of DNA and its loss. Double-Strands -- Breaking (DSBs / DNA Double Strand Breaks); the Fracturing and Fragmenting and Deletion/Loss of your DNA...is the cause why you age and will die 'at the maximum'. no more (or even before...if living a 'short average life'...from some disease). The Epigenetic Clock is the 'Counter' and 'Regulator/Decider'.....it only counts but it is a 'pre-ordained'/'deterministic'/'autoprogrammed'...'script'...that scrolls down. In essence,...the epigenome is why we don't beyond max...because it does not allow it; when DNA is repaired and synthesized, there can be epigenetic changes...but if they don't happen the 'marks' left on the DNA are pretty much permanent (unless using DNA epireprogramming); and thus, you are on a 'downhilll slope', on 'a course towards your end'. It is Quite Stocastic and not so 'entropic'...random-like..not really..it's really 'all been thought' and made/evolved (or God Made if you believe in that)...so, that you die..on time, each time. It's why I often say: ''we got played/outwitted (once again) at our own game''.
Nicholas D...is correct/I share is view....that exercise is only benefitial is Small-to-medium dose...nothing else. Overexercising is extremely detrimental...and is the 'burning the candle by both ends'....don't burn yourself out--too quick..Conserve yourself. That means slowing down...but not being Inter/Amorph neither. Some small exercise has benefits..and will maintain your shape/fitness...your skeletal muscle mass..your grip (grip strength = correlation to death);
if you lose grip strength you are experiencing 'sarcopenia/frailty of age' -- muscle loss/muscle cells (myocytes loss) muscle fiber types loss...with age; if you lose this grip you are closer to your death. It's been repeatedly shown, that grip strenght is a good marker to 'healthspan/health'.
So keep it...by doing some exercise -- not ovexercising. Some, exercise, that's the key word.
Modest...like in most things ''modesty has its pluses''. In other words...just don't overdo it.
Or, 'Don't overdo anything'.
No exercise...same thing, inversely; you don't want to do NO exercise neither; it's bad, you will lose your shape real quick and your muscle mass too; diseases will come just as fast...because you don't keep your health/shape/fitness...with age. So,...some, exercise is best (small to modest..or some small 'sustained robust' exercise bouts...but quickly and quickly done').
There is clearly a 'tradeoff. going on..you obviously need Some muscle mass...but too much mass can also mean too much Insulin Signaling (IGF -> Muscle Mass -> mTOR -> Senescence).
It's why Dwarf mice (and people) live longer lives 'in general'...some don't...many suffer of diseases or health problems --because there is so little Insulin signaling in them...
IGF/EGF/GH/GF/BDNF protects neuron from neurond death...so you Need some insulin signaling...but 'too much is just as bad as too little'...so once again, it's a balance 'gold mean' that must be found.
Just a 2 cents.
PS: Neal is also correct that we're just not made to be sedentary so long...and that yes, exercise is a bit of a 'throwback to the ancient age'...when we were 'nomads'...moving all the tim...and not 'seated in a chair/on our *ss...for hours on end'. With that said...we need to Sit Down..but not forever neither; and 'get our *ss..movin'...plus, yes, all the pollution and crap food/drugs...all this is not healthy in the long run...it only hastens our demise.
PPS: Offtopic....I now know what is biggest cause of Atherosclerosis....it's not so much fat intake (well it is..but not entirely)..it'S that Fat Intake will lead to LDL elevation (except certain PUFAs...polyunsaturates...but the biggest contributor is SFAs Saturated Fats...like palm oil...palmitic acid, stearic acid....etc...these short fats are causal to atherosclerosis).
But, again, it's not so much the Saturated Fats, themselves...the culprit..
drum...roll..
it's your Guts...microflora/intestinal flora..the Biggest Contributor to Atherosclerosis.
Gut Dysbosis is a big reason why LDL levels rise and macrophages can't switch to their 'antiinflammatory mode'...and stick to 'inflammation mode' (via LDL receptor);
---> there are gut bacterias that contribue to atherosclerosis -in a near 1:1..fashion...
Mainly the TMAO producing bacterias (trimethylamine-oxide producing); bacterias produce TMA and later this TMA is conjugated with microbial TMA lyase and liver FMOs...which cause formation of TMAO as end product. This TMAO is VERY toxic and oxidizes the arteries...studies have found that there was a very close correlation between blood TMAO levels and atherosclerosis progression. So...your intestinal flora is the Main culprit of atherosclerosis; when TMAO levels Reduced...well,, funnily, the atherosclerosis progress reduced too..
Obviously ,this is a type of Oxide (TMA -O); and clearly it oxidize the milieu of arteries, which cause ROS and calficication of the arteries (excess calcium signaling and calcary deposits) which will cause arteries stiffening and atherolesions to form (And then, Fill with LDL fat -- fat pockets which will not be 'phaged' by foam cells/macrophages); in other words, atherome/plaque formation in arteries. So...what to do now, well, reduce saturated fat intake, extremely important, but not only that....TMAO/TMA lyase Inhibitor...TMA/TMAO inhibition by Gut Flora Reformation Change...in essence, change your intestinal flora...using 'bio-probiotics'...like yogurt prebiotics...bacterial cultures that once ingested...change your gut flora towards a Healthy flora...that Does Not produce TMAO...the big culprit of this TMAO..is your intestinal bacteria.
When you feed them Saturated Fats , they increase Choline....this choline is then used in conjuction with bacteria to create the formation of TMA..this TMA is then conjugated and oxidized..to TMAO...and this wreaks havoc in your blood and your arteries. So, be careful with fat ingestion...it will increase choline..and bacterial culture will 'overproduce' TMA...which well end up as TMAO..down the line. Neutralizng TMAO is a solution..but it's better to solve the cause than put a 'band-aid' solution..so the cause..is the bacterias (making TMA). For example, Berberine or other herbs...reduce atherosclerosis..not so much because of stopping TMA itself...but because they Change the gut flora composition..towards a healthy gut flora.
Then...there are no more 'TMA-producing bacterias'...in your colomn/intestines. Same thing for Total Cholesterol intake (you want to raise your HDL and lower your LDL..but you need some cholesterol ---mostly, the High Density Lipoprotein cholesterol...), with that said, when the levels are too high this can contribute to TMAO/bacterial choline/TMA formation...once again...and you end up with a 'self-defeating' purpose...where you might improve cholesterol levels but you did not solve the culprit which is your intestinal flora (the contributor of blood TMAO).