Controlled Bodily Impact-Trauma As Hormetic

[JohnG]

I am VERY interested in hormesis and have been studying the scientific papers and literature on it with much gusto over recent months since first becoming aware of it. I have also been doing a lot of thought and hypothesizing about the possible mechanisms of action of hormesis, as well as trying to imagine new and effective "hormetics."

I could, and might, write a lot more about my ongoing investigations in more detail at some point, however I thought I'd start my first post here with a possible hormetic that I have been considering, but for which I have found very little information: controlled physical trauma.

I realize this method of hormesis might seem a bit more confronting even than the general thrust of hormesis, but I think that it generally conforms to theoretical principles of hormesis, and even has some particular theoretical underpinnings that more commonly discussed hormetics do not.

The mainstream consensus is that physical strength/resistance training fundamentally works by a mechanism of inducing "microtrauma" to muscular and related structures, followed by sufficient rest to allow for repair(or, perhaps "over-repair".) This then results in additional strength. There are also treatments like micro-needling and dermabrasion that damage superficial layers of the skin with the hopes that the skin qualities will improve by the action of repair, regrowth and/or regeneration.

My idea/hypothesis is that controlled impact trauma to the body might also have beneficial effects by inducing overcompensation/over-repair and activating general maintenance/repair/regeneration systems in the body.

The basic principle would be to impact the body in a very controlled manner: sufficient to cause damage, but with a magnitude of damage, and a subsequent rest-from-trauma period, that allows full repair(and hopefully "over-repair")

The impact/s could be along the lines of anything from snapping a rubber band against the skin to taking hits from padded weighted implements(not unlike simulating punches from boxing - although I'd suggest avoiding any forceful head impacts.) Generally, the idea would be to avoid breaking the skin, but rather to compress the tissues in a very transitory fashion. The resulting damage might be anything from slight redness for a few minutes, to a significant bruise that may take some time to disappear.

The impacts and damage should be very well controlled and defined, as should the requisite rest period. It would be important to get the "dose" magnitude, duration and frequency right. The damage must be fully repairable and not too stressful for the body. A gradual induction and then increase in dose would also likely be desirable.

For instance, more fleshy areas with strong underlying bones, such as thighs, could probably take more forceful impacts without major risk, whereas areas with reduced flesh thickness, weaker bones and/or sensitive structures(e.g. underlying organs, eyes) like hands, would be subjected to lesser(or perhaps no) impacts.

There are several theoretical reasons I have devised as to why controlled body impact trauma may be especially suitable as a hormetic:

1. Evolution. Animals, including humans and our close relatives, have almost universally been subject to relatively regular bodily impact trauma. This sort of hormetic is thus very essentially "natural" in a way that many hypothesized chemical hormetics and similar aren't. Thus, we have evolved very specific repair, maintenance and regeneration capabilities to deal with it.

2. Dose/response feedback. We have also evolved very obvious subjective/conscious/perceptual feedback responses to this sort of damage. We can usually immediately feel the damage, we can gauge its intensity, we can see the results, and very often we can even immediately accurately guess at how much damage has been done and roughly how long it will take to heal. We are also generally aware of when full healing has subsequently occurred. Again, because it is such a natural form of stress, we are very attuned to "dosage", whereas we cannot even perceive any obvious effects of a dose of many less natural theoretical hormetics like various chemicals. This feedback could potentially allow for much easier perfection of dosage for the individual.

3. It is "topical." Since this hormetic could be applied externally, or "topically", it could be much easier to control exactly where and to what magnitude it is applied it. Perhaps just give a little slap to a single finger to induce minor damage, whilst giving more of a hefty wack to a thigh. Topical medical treatments in general have this advantage. Many other hormetics are "systemic", in that they are ingested or otherwise make their own way throughout the body, taking highly complex routes through the bodily system, interacting in many complex ways with different magnitudes with various systems, all in a very uncontrolled manner.

There is much more to this, and other hormetics, that I have considered, but I will stop here for the moment. I'm looking to engage in some significant discussion on this and other related hormesis subjects, so please respond if you're interested and/or have any input or insight to share.

[Todd Becker]

John,

Thanks for your interesting post.  This is definitely one of the most unusual applications of hormesis that I've heard of, and it sounds like you are the creator of the idea.  My first reaction was:  this is pretty far out there.  But in reading your post, there may be something to it. For one thing, the analogy with microtrauma as the mechanism of muscle growth in weight lifting is apt.  Yet, in the case of the type of "macrotrauma" you are proposing, I'm having trouble envisioning exactly what the end result would look like and what the benefits would be--and why anyone would want to do this.  There is a fine line between what I call "Hormetism" (applied hormesis or hormetics), and what some people perceive as masochism.  The way I usually explain the difference is that hormesis involves a short term "pain" that results in a long term "gain", where the gain objectively far outweighs the pain. By contrast, masochism seems to involve pursuit of pain for the sake of pain, where the pain is somehow perversely experienced as pleasure in and of itself, and where there is no objective benefit. Some of the theoretical basis behind this is explained on my blog post on The Opponent Process Theory of Richard Solomon.  So I ask the same question of you:  what is the long term benefit?

For example, in what respect do you think that skin qualities would "improve" by controlled abrasion or impact?  I think this would tend to produce tougher, thicker skin.  That could be a plus in certain locations--like the soles of the feet for barefoot runners, or the fingers of a guitarist -- but would you really want callused skin more generally on your arms, legs, torso or face?  Most people would aesthetically prefer softer, more tender skin in those regions, unless there is some specific need for tougher skin.

On the other hand, I could see a benefit to strengthen the skeletal structure through controlled impact.  If done properly, using the appropriate dose-response relationships and gradually ramping up the impact, this could be a way to build bone density and joint strength as a preventive measure to minimize the risk of injury during sports or other intense activities.  Some of this is already done during weight training, but perhaps your suggestion would be to use additional exercises such as jumping or running into punching bags or padded walls, as is done by boxers, football players or other athletes.

Do you have any references or links to any research in this area that is at least suggestive of benefits?  Or are you willing to be a guinea pig for your own idea to test it out and report back results?  Some folks on this forum have started "personal pages" or "challenges" where they set forth some goals and track their progress, and perhaps invite others to do the same.

I look forward to hearing more about this.

Todd

[JohnG]

Hi Todd. Great site.

So I ask the same question of you:  what is the long term benefit?

The hoped-for long term benefit, is a movement of the "organism" toward a generalized state of upregulated repair, regeneration and maintenance. The theory being that this may lead to life-span and health-span increases - those are my major goals as far as hormesis is concerned.

For example, in what respect do you think that skin qualities would "improve" by controlled abrasion or impact?  I think this would tend to produce tougher, thicker skin.

I don't know for certain what the results would be for the skin. It may produce tougher and thicker skin, and in fact aging has been associated with thinning of the skin, so if this occurred it might help counteract this aspect of aging. Again I'm just going to have to say upregulation of repair, regeneration and maintenance.

Science and biogerontology has yet to come to any meaningful consensus, or experimental evidence as to why functioning declines in aging. Lacking this knowledge is obviously a huge impediment to implementing strategies of slowing, stopping or reversing aging and functional decline.

If hormesis works by using damage/stressors(or damage simulators aka "mimetics") to activate and upregulate the natural ability of the body to heal itself, it may be possible to use this to let the body "do the work for us" without having to understand in detail the mechanism that allow this to happen. This is why I think hormesis shows much potential promise.

Do you have any references or links to any research in this area that is at least suggestive of benefits?

I know several world champion boxers who lived into old age.  Other than that, I don't have research in this area. I haven't done much searching yet in that exact area, but I have laid the groundwork in several other ways, like investigating how healing is currently understood to occur, the differences between repair with scar tissue and regeneration, which particular cells types are thought to be regenerative, what sorts of damage is repaired the best, the dangers in specific types of trauma, and masses of research of papers on hormesis etc.

Or are you willing to be a guinea pig for your own idea to test it out and report back results?  Some folks on this forum have started "personal pages" or "challenges" where they set forth some goals and track their progress, and perhaps invite others to do the same.

There's a chance I may be a guinea pig for this, but I need to do much more research first. I'm also weighing the pros and cons and unknowns - when would it be reasonable to expect significant progress into anti-ageing to occur by science, how old would I be at that time etc.

I've been investigating and brainstorming various possible hormetics/stressors that I think could upregulate and activate natural repair systems and I think this is one of the more promising for various reasons(including the three I listed at the end of my last post.)

[JohnG]

By the way, as far as "masochism" goes, which is obviously not my goal....but I think I'd rather take a few punches(or their closely-controlled simulations) every so often than spend my life on caloric restriction or to have to endure several cold showers per week.

[Todd Becker]

John, I'm really enjoying your posts.

The hoped-for long term benefit, is a movement of the "organism" toward a generalized state of upregulated repair, regeneration and maintenance. The theory being that this may lead to life-span and health-span increases - those are my major goals as far as hormesis is concerned....If hormesis works by using damage/stressors(or damage simulators aka "mimetics") to activate and upregulate the natural ability of the body to heal itself, it may be possible to use this to let the body "do the work for us" without having to understand in detail the mechanism that allow this to happen. This is why I think hormesis shows much potential promise.

...I know several world champion boxers who lived into old age.  Other than that, I don't have research in this area.

Presumably, Muhammed Ali was not among the boxers in this group    ...just joking!  Obviously, we both realize that the principle of hormesis indicates there is an optimum level of stress.  While it is usually articulated as "a little of a bad thing is good for you", I prefer to think of it as "too much of a good thing is bad for you".  Ali just had way too much of the good thing, and in the wrong place -- the head.

The most interesting question you raise is whether or not hormesis operates as a more generalized or a more specific effect: just how general are the upregulated repair and regeneration mechanisms you refer to?  It is clear that the microtrauma of weight lifting leads to localized muscle growth, plus lens therapy leads to improve visual acuity, and constraint-induced movement therapy restores function and agility of the affected limbs.  But I have not seen arguments that there are systemic benefits from these localized types of hormetic adaptation, except in some limited cases, e.g. weight lifting can upregulate insulin receptors in muscles and thereby improve insulin sensitivity.

On the other hand, caloric restriction leads to a wide range of benefits, including insulin reduction and BDNF stimulation, leading to reversal of metabolic syndrome, cognitive benefits and inhibition of certain aging processes.  Likewise, cold showers induce thermogenensis which initiates a cascade of regulatory changes that have been linked to benefits as diverse as weight loss and anti-depressive effects.  And UV exposure induces not only the protective effect of Vitamin D, but anti-cancer benefits from the Vitamin D and related metabolites. Radiation probably also has some systemic hormetic effects.

So there are probably instances of both local and systemic hormesis, and the generality of hormesis varies.

Then my question for you is:  what is the evidence that mechanical trauma is associated with more general systemic hormesis, as opposed to local benefits in strengthening the musculoskeletal system?  I'd love to see any research you can find on this topic.

By the way, as far as "masochism" goes, which is obviously not my goal....but I think I'd rather take a few punches(or their closely-controlled simulations) every so often than spend my life on caloric restriction or to have to endure several cold showers per week.

Well, I guess each of us needs to "choose our poison", to use an old expression.  I find cold showers invigorating, and after a few weeks of taking them, there is not even a hint of the pain and discomfort experienced when I started, whereas the pleasure and joy last all day.  My best explanation for them is the Opponent-Process Theory that I've blogged about.  Also, the caloric restriction of IF is extremely comfortable and even energizing when done the right way -- there is absolutely no sense of deprivation.  The key for me is to include a high level of protein and fat in the diet (though I don't avoid carbohydrates), to eat delicious and highly varied food, and to eat to fullness the 1 or 2 meals I eat each day.  Every meal is a delight, and I don't worry about food between meals. 

I will start taking controlled punches once I see the evidence for benefits...and so long as it also makes me feel good afterwords.  Although this is getting a bit close to joke about the guy who was hitting himself on the head, and when asked "why?" responded: "because it feels so good when I stop".  The joke assumed the guy to be an idiot, but we should always be willing to revisit our misconceptions based on new evidence.

Todd

[JohnG]

Presumably, Muhammed Ali was not among the boxers in this group  Wink  ...just joking!........Ali just had way too much of the good thing, and in the wrong place -- the head.

There's potentially something to be learnt from brain-damage caused by boxing in regard to hormesis. As I said earlier, I've done quite a lot of background research in support of my hypothesis of impact trauma hormesis - one particular thing I've investigated is exactly what type of damage can be fully repaired.

One of my basic assumptions is that it's no good inducing damage/stress if that damage/stress is incapable of being sufficiently repaired/regenerated. The theory is to either keep the damage and repair balanced(and so keep the organism in healthy homeostasis), or to induce a response to a damage/stressor that overcompensates with repair - which is quite possibly what occurs with muscle hypertrophy seen in resistance exercises.

My research thus far has shown that brain and heart tissues are considered to be amongst the least regenerative and least well-repaired structures in the human body. So the example of boxers' with brain damage makes perfect sense from that perspective - heavy blows to the head are probably not a good idea since brain tissues do not seem to have good repair/regenerative capabilities.

I'm hoping that by understanding the "basic" physiological mechanisms(as well as their evolution and other aspects) involved in damage and repair, I can develop the most efficacious hormetic stressors and doses. This may be even more important since strong experimental evidence could be lacking for a long time to come(maybe too long for some people to wait for such evidence, if they are interested in attempting to gain benefits from this type of hormesis for themselves.)

Also, boxers' are one of the limited number of models for impact trauma hormesis that I can think of, so they could be very useful in general....

Obviously, we both realize that the principle of hormesis indicates there is an optimum level of stress.  While it is usually articulated as "a little of a bad thing is good for you", I prefer to think of it as "too much of a good thing is bad for you".

Absolutely. I've developed a basic model of this actually, but extended it to fit with my research and general hormesis hypothesis and observations. You've probably heard of the so-called hormetic "biphasic dose response", or the "two-phase" dose response. One reponse phase is often called "stimulation" due to a low dose, the other response phase is often called "inhibition" due to a high dose.

What I propose is a triphasic response. I'm quite surprised, actually, about the lack of mention of a triphasic hormetic response. The triphasic response has been seen experimentally, and is visually represented on this graph(which you have linked to on your blog):
http://upload.wikimedia.org/wikipedia/commons/thumb/b/b7/Hormesis_dose_response_graph.svg/220px-Hormesis_dose_response_graph.svg.png

As can be seen, the very lowest dose actually results in inhibition, then the mid dose results in stimulation, then the largest dose once again results in an inhibiting response. The lowest dose, with the inhibiting response, is the one that seems to have lacked much attention from the hormetic literature to this point, but I think it could be very important.

So, I'll describe, in simple terms what my triphasic model is. First I'll replace "inhibition" with "damage" and "stimulation" with "repair." They don't have to be represented in this way necessarily, but it's useful for clarity and intuitiveness in my explanation. And I'll assume that resistance/strength training is the "dose." So here are the axioms of my triphasic response hormetic hypothesis:

1. Low doses will cause low levels of damage, but will not activate repair mechanisms sufficiently to counteract this damage - this will lead to damage by atrophy.("Low dose is harmful")

2. High doses will cause high levels of damage, and will activate maximal repair mechanisms, but the repair mechanisms will not be sufficient to cope with the high level of damage - this leads to damage by exhaustion/injury("High dose is harmful")

3. Medium doses will cause medium level of damage, and will activate repair mechanisms sufficiently to repair the medium levels of damage - this leads to a desirable balance of damage and repair, or maintenance repair/homeostasis("Medium dose is beneficial")

In summation, my hypothesis is: too little damage doesn't activate body repair mechanisms sufficiently, leading to atrophy, too much damage overwhelms repair mechanisms and lead to injury/exhaustion, but just the right amount of damage leads to a balance between damage and repair activation that results in ongoing body maintenance.

Obviously this triphasic model is supported by evidence from people who fail to exercise sufficiently and are subject to atrophy/wasting. It explains the inhibition seen at very low doses on the hormetic scale.

I'll respond to the rest of your post in my next reply....

[jared33]

The mainstream consensus is that physical strength/resistance training fundamentally works by a mechanism of inducing "microtrauma" to muscular and related structures, followed by sufficient rest to allow for repair(or, perhaps "over-repair".) This then results in additional strength. There are also treatments like micro-needling and dermabrasion that damage superficial layers of the skin with the hopes that the skin qualities will improve by the action of repair, regrowth and/or regeneration.

My idea/hypothesis is that controlled impact trauma to the body might also have beneficial effects by inducing overcompensation/over-repair and activating general maintenance/repair/regeneration systems in the body.

The basic principle would be to impact the body in a very controlled manner: sufficient to cause damage, but with a magnitude of damage, and a subsequent rest-from-trauma period, that allows full repair(and hopefully "over-repair")

This is an interesting idea, John.  There is a bodybuilding technique called plyometrics, which uses agressive body motions like jumping an lunging to build power.  As I understand it, plyometrics puts a lot of stress on your bones and joints and cause a repair mechanism that leads to improved strength and power.  Of course, you can overdo it and injure yourself.  But I think you are advocating a more moderate approach where the repair and regeneration compensate for any damage, and injury is avoided. 

Right?

[JohnG]

The most interesting question you raise is whether or not hormesis operates as a more generalized or a more specific effect: just how general are the upregulated repair and regeneration mechanisms you refer to?  It is clear that the microtrauma of weight lifting leads to localized muscle growth, plus lens therapy leads to improve visual acuity, and constraint-induced movement therapy restores function and agility of the affected limbs.  But I have not seen arguments that there are systemic benefits from these localized types of hormetic adaptation, except in some limited cases, e.g. weight lifting can upregulate insulin receptors in muscles and thereby improve insulin sensitivity.

I'm not sure about that. I can't (yet) cite any particular studies regarding the more systemic effects of weight training, but I am aware of claims made by the mainstream psychological community of beneficial psychological benefits of strength exercises, to give one example off the top of my head - as one example of more generalized effects.

So there are probably instances of both local and systemic hormesis, and the generality of hormesis varies.

Then my question for you is:  what is the evidence that mechanical trauma is associated with more general systemic hormesis, as opposed to local benefits in strengthening the musculoskeletal system?  I'd love to see any research you can find on this topic.

This is indeed one of my central questions. The short answer is: I have yet to do any significant study in this area, so I don't have any evidence for more general effects yet. I'm already overwhelmed with research avenues, but I do intend to investigate this avenue too.

My current, initial, stance, is that I think it shows promise for systemic effects based on evolutionary theory.

If we assume that biological systems are adapted for the transmission of genes and the continuance of the species, then there is the argument that when an organism is faced with situations that threaten its chances of successfully reproduction, it tends to move into a defensive "maintenance" mode instead of a reproductive mode. This is one of the theories given for the effects of caloric restriction.

One theory of caloric restriction is that it simulates starvation. Starvation is associated with biological and environmental states that are not conductive to successful reproduction - weakness, lack of food for the young etc. The adapted response, thus, is theorized to be a generalized movement of the organism toward survival and maintenance "modes." The idea being that reproductive chances are highest if the organism can survive the starvation period, and then reproduce once circumstances are more conductive to reproduction. So survival is prioritized.

I would tentatively hypothesize that physical trauma is another "stressor", like starvation, that would have had a long and intimate role in the evolution and adaption of most animals, and that the adaptions to it would be rather similar to starvation(and caloric restriction) - prioritize survival and maintenance. Likewise, if starvation is too severe it overwhelms the organism, just as if physical impact trauma is too severe it overwhelms the repair mechanisms of the organism.

(It's possible to see death/disease by starvation, death/disease by obesity, and then maintenance by just the right amount of food as conforming to the triphasic hormetic dose response I mentioned earlier too.)

Well, I guess each of us needs to "choose our poison", to use an old expression.  I find cold showers invigorating, and after a few weeks of taking them, there is not even a hint of the pain and discomfort experienced when I started, whereas the pleasure and joy last all day.  My best explanation for them is the Opponent-Process Theory that I've blogged about.

Yeah, I was just trying to make a point that everyone might have their own preferred poisons so to speak. The thought of cold showers is horrible to me, but then, I might not find it so bad, particularly if there was a slow decrease of temperature(I think the acclimatization to stressors, by incremental intensity increase, might be an important fundamental principle for hormesis.) To me, taking a decent punch doesn't seem too bad, for whatever personal idiosyncratic reason/s and background. I really don't see it as so very different to hormesis in general, so I was arguing for that case.

Cold water immersion is in fact on my big list of possible hormetic stressors, and I think it may have some evolutionary backing too. I was watching a documentary just yesterday about bonobo chimpanzees, and I noticed one chimp wade into a river to retrieve some food that was floating on the surface of the water(it looked like it may have been fruit which had dropped down from an overhanging tree.) So could definitely be some adaption pressures for it.

Intuitively, not having experimented with it - I get the feeling that I'd prefer to plunge into a pool of cold water rather than receive my dosage from a shower head. I'd also suggest possibly just intermittent exposure to cold air without much clothing.

I can see parallels in subjective response to jumping into a cold body of water and taking a slap to the face(physical impact trauma.) In fact, I get the feeling that there is a pattern of "shock to system" followed by an energizing and vitalizing after-reaction that leads to a sharpening of the senses and mind. Maybe this is a guiding response to look for. My research into circadian rhythms, which might be thought of as sine-waves, suggests that with ageing and decrease in function, the amplitude of these rhythms/waves decreases, so that there are less lows and less highs. A contraction, a loss of contrast. I find it interesting to tie this all together, and suggest that maximizing contrast, maximizing the highs and the lows(maximizing "stress/rest" as a I call it.) could be a key.

(As an aside, have you ever accidentally been in the path of a megaphone or other very loud sound? Again, it's a very transitory "shock", a high intensity brief stress that "wakes you up." It's almost like you feel more alive immediately afterward. And how often do you hear elderly people blaring music? Maybe an example of the general contraction of amplitude of stressors.)

Also, the caloric restriction of IF is extremely comfortable and even energizing when done the right way -- there is absolutely no sense of deprivation.  The key for me is to include a high level of protein and fat in the diet (though I don't avoid carbohydrates), to eat delicious and highly varied food, and to eat to fullness the 1 or 2 meals I eat each day.  Every meal is a delight, and I don't worry about food between meals.

Again, with caloric restriction, I was being a bit provocative to argue my point about the punches not being so different to any other hormetic regime. But, CR is different to intermittent fasting. I think intermittent fasting is far more desirable from the point of view of "withstanding the pain"(if you'd even call it "pain.") I've done some very limited IF myself and I found it easy, and even energizing and vitalizing(though that may have been more a placebo effect.) I'm definitely considering IF.

I will start taking controlled punches once I see the evidence for benefits...and so long as it also makes me feel good afterwords.  Although this is getting a bit close to joke about the guy who was hitting himself on the head, and when asked "why?" responded: "because it feels so good when I stop".  The joke assumed the guy to be an idiot, but we should always be willing to revisit our misconceptions based on new evidence.

One of my guiding principles for most of my life has been to avoid stressors, but it's looking more and more like that principle is going to be turned on it's head - the evidence and theory have convinced me that's the way to go, and so I likely will.

I'm looking at medium and long term benefits - life-extension and health-extension are two of my main goals for hormesis, but I'd love short-term effects too. For long term benefits, I'm not sure that there is all that strong evidence for any of the commonly proposed hormetic regimes. Caloric restriction, if it is a hormetic, might have ths strongest evidence in favour, but even the first experiments on long-lived primates have yet to be completed.

I'm not sure there are any really relevant experiments on body-impact trauma as a hormetic - I might be one of the first to imagine it. If you wait for experimental results, you may be waiting a very long time - maybe even too long if you're interested in life and health extension benefits that it may provide.

But then, there are obviously risks involved when engaging in something that doesn't have strong evidence. It's risk vs reward. What I know is that the current average lifespan in developed countries is around 80 years, and many people are in somewhat poor shape in later years. I also believe that medical science may develop ways to significantly slow, stop and/or reverse ageing, and that this could happen in the not too distant future. I want to do everything I can to try to live, and live in a strong and healthy state, until that time. We might be living right on the cusp of having access to such technologies, and it would be a tragedy to just miss out. The older people get, the slimmer their chances of seeing such a time, and the more reasonable it may seem to try unproven, but promising, avenues that could help them see the end of death and decay altogether.

[JohnG]

This is an interesting idea, John.  There is a bodybuilding technique called plyometrics, which uses agressive body motions like jumping an lunging to build power.  As I understand it, plyometrics puts a lot of stress on your bones and joints and cause a repair mechanism that leads to improved strength and power.  Of course, you can overdo it and injure yourself.  But I think you are advocating a more moderate approach where the repair and regeneration compensate for any damage, and injury is avoided. 

Right?

Yes. The idea is to induce enough stress/damage to activate repair mechanisms, but to avoid inducing so much stress/damage that the repair mechanisms are unable to fully repair the damage.

There's another process called "collagen induction therapy" that works on the same general principle and has had some research done on it. Here's one study:
http://www.ncbi.nlm.nih.gov/pubmed/20413357

Basically, lots of superficial holes are made in the skin by puncturing it with needles. Very much like how tattoos are made but without adding any ink, and also kind of like acupuncture(but the pins puncture the skin more densely.) Here is a device that achieves the skin puncturing, it involves a small rotating drum with needles protruding from it which is rolled over the skin:
http://www.vivida.co.za/medical

The trauma of the pinholes is enough to cause the natural repair mechanisms in the skin to be activated, but the pinholes are small enough and spaced out enough so that the damage is not so severe that the repair mechanisms are overwhelmed. The activated healing mechanisms of the skin end up "over-repairing" the skin(just like muscle hypertrophy in strength exercises) in response to the trauma and the skin is actually stronger and healthier afterward.

 

[JohnG]

The basic principle would be to impact the body in a very controlled manner: sufficient to cause damage, but with a magnitude of damage, and a subsequent rest-from-trauma period, that allows full repair(and hopefully "over-repair")

This is an interesting idea, John.  There is a bodybuilding technique called plyometrics, which uses agressive body motions like jumping an lunging to build power.  As I understand it, plyometrics puts a lot of stress on your bones and joints and cause a repair mechanism that leads to improved strength and power.  Of course, you can overdo it and injure yourself.  But I think you are advocating a more moderate approach where the repair and regeneration compensate for any damage, and injury is avoided. 

Right?

If I do decide to start experimenting with this, I'm actually contemplating building a device that could deliver very calibrated, controlled and consistent impacts. Something like a spring that powers a weighted impacting plate. The spring could be retracted the same amount every time to generate a known and safe impact force. The angle that the impact occurs, the position the body is held etc would all be controlled. The impact force would be varied based on impact location on the body. The impact level could be ramped up over time to allow for acclimatization.

The idea is to get the impacts just into the zone where they activate the right amount of repairs without doing any irreparable damage. "Fractionation" could be used, meaning that the bruises would be spaced out across the body, leaving undamaged areas in between, to further guarantee that repair mechanisms were not overwhelmed.

[JohnG]

I'm not suggesting adding this to a hormesis regime, but it does lend still further support for the general idea - apparently, there's some evidence to suggest that broken bones heal back stronger than the original(from the FDA website):
http://web.archive.org/web/20071214170507/http://www.fda.gov/fdac/features/396_bone.html

"When a Bone Breaks

Fracture breaks continuity of bone and of important attached soft tissue--including blood vessels, which spill their contents into surrounding tissue.

Even before treatment, the body automatically seeks to repair the injury. Inflammatory cells rush to destroy, dilute or isolate invaders and injured tissue. Tiny new blood vessels called capillaries begin growing into the site. Cells proliferate. The injured person usually must endure pain, swelling, and increased heat at the breakage site for one to three days.

New tissue bonds the fractured bone ends with a soft callus, a mass of connective tissue and exudate (matter escaped through blood vessel walls). Remodeling begins. Within a few months, a hard callus replaces the soft one. Remodeling restores the inner canal.

Once restoration is complete, which may take years, the healed area is brand new, without a scar. Usually thicker, the new bone may even be stronger than the old, Yahiro says, adding that if the bone should break again, it's unlikely to be at the same place."

[Sanchiaza]

I'm reading this thread with a kind of horrified fascination coupled with a desire to start patting and tapping my face in areas where I figure I could do with some repair to a more youthful state!

Previous times I've read posts on this thread, the idea that came to mind was running and other aerobic activity. Women at risk of osteoporosis are often advised to do so-called "bone jarring" exercise in an effort to maintain bone density and bone calcium levels.

I have a question - JohnG, is this self-experimentation / research you are embarking on, or with other human volunteers? I really hope so because I think that any research along these lines on animals would be cruel.

[JohnG]

I have a question - JohnG, is this self-experimentation / research you are embarking on, or with other human volunteers? I really hope so because I think that any research along these lines on animals would be cruel.

It's early stages, but I'm most expecting self-experimentation, if anything. Having other human volunteers might be good though.

[JohnG]

Early days, but some potentially supportive evidence as regards lifespan extension and bodily trauma:

http://www.ncbi.nlm.nih.gov/pubmed/9415098

Exp Gerontol. 1996 Nov-Dec;31(6):699-704.
Rejuvenation of the disposable soma: repeated injury extends lifespan in an asexual annelid.

Martínez DE.

Department of Biology, St. Lawrence University, Canton, New York 13617, USA.
Abstract

The disposable soma theory of senescence proposes that aging is the result of the accumulation of somatic damage with age resulting from insufficient somatic maintenance and repair. Comparative studies that show a positive correlation between longevity and DNA excision repair efficiency in mammals provide support for the theory but their validity has been questioned. A more satisfactory approach to investigate the role of somatic damage accumulation in aging would be to manipulate experimentally the levels of somatic repair and observe its effect on longevity. Here I report the results of studies in the asexual annelid Paranais litoralis where I have experimentally extended the worms' lifespan by subjecting them to repeated injury. I propose that repeated injury enhanced the normal level of repair of the worms, resulting in a rejuvenation of the soma. These results provide experimental support for the disposable soma theory of senescence.

PMID: 9415098 [PubMed - indexed for MEDLINE]

[jared33]

Early days, but some potentially supportive evidence as regards lifespan extension and bodily trauma:

...The disposable soma theory of senescence proposes that aging is the result of the accumulation of somatic damage with age resulting from insufficient somatic maintenance and repair.

Quite intriguing, John.  Kirkwood's 'disposable soma' theory of aging has been gaining quite a bit of credence lately.  It makes sense that the organism has to make a compromise in whether to allocate resources to reproduction vs. maintenance and growth, etc.   This Wikipedia article gives some more background:

http://en.wikipedia.org/wiki/Evolution_of_ageing#Disposable_soma_theory

However, the article also mentions that it is not easy to reconcile the benefits of caloric restriction with the disposable soma theory:

The disposable soma theory has great appeal because its basis is so sensible and intuitive, but there are arguments against it. The theory clearly predicts that a shortage of food should make the compromise more severe all around; but in many experiments, ongoing since 1930, it has been demonstrated that animals live longer when fed substantially less than controls. This is the caloric restriction (CR) effect,[8] and it cannot be easily reconciled with the Disposable Soma theory. Though by decreasing energy expenditure the damage generated (by free radicals for instance) is expected to be reduced and the total energy budget might indeed be reduced, but the investment in repair function might still be relatively the same. But dietary restriction has not been shown to increase lifetime reproductive success (fitness), because when food availability is lower reproductive output is also lower. So CR does thus not completely dismiss disposable theory.

So you might want to think about how this relates to your theory that induced damage will extend lifespan. Do you see an analogy between bodily impact and caloric restriction as far as how they might affect aging?