Elastic Limit Quotes

In a wide variety of human activity, achievement is not possible without discomfort.

You judge what’s sustainable based not only on how you feel, but on how that feeling compares to how you expected to feel at that point in the race.

There were two now where they had been three. David's death had dismantled the triangle, and an enclosed space was now open. Two points are unreliable; with nothing to anchor them, there is nothing to stop them drifting in opposite directions. If it is string that binds, it will eventually snap and the points will separate; if elastic, they will continue to part, further and further, until the strain reaches its limit and they are pulled back with such speed that they cannot help but collide with devastating force.

endurance is “the struggle to continue against a mounting desire to stop.

This shows that simply getting fitter doesn’t magically increase your pain tolerance; how you get fit matters: you have to suffer.

The human spirit is like an elastic band. The more you stretch, the greater your capacity.

the struggle to continue against a mounting desire to stop.

A runner is a miser, spending the pennies of his energy with great stinginess, constantly wanting to know how much he has spent and how much longer he will be expected to pay. He wants to be broke at precisely the moment he no longer needs his coin.

turns out that, whether it’s heat or cold, hunger or thirst, or muscles screaming with the supposed poison of “lactic acid,” what matters in many cases is how the brain interprets these distress signals.

we can stretch our personalities, but only up to a point. Our inborn temperaments influence us, regardless of the lives we lead. A sizable part of who we are is ordained by our genes, by our brains, by our nervous systems. And yet the elasticity that Schwartz found in some of the high-reactive teens also suggests the converse: we have free will and can use it to shape our personalities. These seem like contradictory principles, but they are not. Free will can take us far, suggests Dr. Schwartz’s research, but it cannot carry us infinitely beyond our genetic limits. Bill Gates is never going to be Bill Clinton, no matter how he polishes his social skills, and Bill Clinton can never be Bill Gates, no matter how much time he spends alone with a computer. We might call this the “rubber band theory” of personality. We are like rubber bands at rest. We are elastic and can stretch ourselves, but only so much.

The human mind is only capable of absorbing a few things at a time. We see what is taking place in front of us in the here and now, and cannot envisage simultaneously a succession of processes, no matter how integrated and complementary. Our faculties of perception are consequently limited even as regards fairly simple phenomena. The fate of a single man can be rich with significance, that of a few hundred less so, but the history of thousands and millions of men does not mean anything at all, in any adequate sense of the word. The symmetriad is a million—a billion, rather—raised to the power of N: it is incomprehensible. We pass through vast halls, each with a capacity of ten Kronecker units, and creep like so many ants clinging to the folds of breathing vaults and craning to watch the flight of soaring girders, opalescent in the glare of searchlights, and elastic domes which criss-cross and balance each other unerringly, the perfection of a moment, since everything here passes and fades. The essence of this architecture is movement synchronized towards a precise objective. We observe a fraction of the process, like hearing the vibration of a single string in an orchestra of supergiants. We know, but cannot grasp, that above and below, beyond the limits of perception or imagination, thousands and millions of simultaneous transformations are at work, interlinked like a musical score by mathematical counterpoint. It has been described as a symphony in geometry, but we lack the ears to hear it.

Just like a smile or frown, the words in your head have the power to influence the very feelings they’re supposed to reflect.

wide variety of human activity, achievement is not possible without discomfort.

I propose the following definition of the nation: it is an imagined political community—and imagined as both inherently limited and sovereign. It is imagined because the members of even the smallest nation will never know most of their fellow-members, meet them, or even hear of them, yet in the minds of each lives the image of their communion… The nation is imagined as limited because even the largest of them, encompassing perhaps a billion living human beings, has finite, if elastic, boundaries, beyond which lie other nations… It is imagined as sovereign because the concept was born in an age in which Enlightenment and Revolution were destroying the legitimacy of the divinely-ordained, hierarchical dynastic realm… Finally, it is imagined as a community, because, regardless of the actual inequality and exploitation that may prevail in each, the nation is always conceived as a deep, horizontal comradeship. Ultimately it is this fraternity that makes it possible, over the past two centuries, for so many millions of people, not so much to kill, as willingly die for such limited imaginings. —Benedict Anderson

The limits of endurance running, according to physiologists, could be quantified with three parameters: aerobic capacity, also known as VO2max, which is analogous to the size of a car’s engine; running economy, which is an efficiency measure like gas mileage; and lactate threshold, which dictates how much of your engine’s power you can sustain for long periods of time.

What’s crucial is the need to override what your instincts are telling you to do (slow down, back off, give up), and the sense of elapsed time. Taking a punch without flinching requires self-control, but endurance implies something more sustained: holding your finger in the flame long enough to feel the heat; filling the unforgiving minute with sixty seconds’ worth of distance run.

endurance is “the struggle to continue against a mounting desire to stop.”5 That’s actually Marcora’s description of “effort” rather than endurance (a distinction we’ll explore further in Chapter 4), but it captures both the physical and mental aspects of endurance. What’s

My heart is elastic. I realize it for the first time. For so long I thought there was a limit to how much love I could hold and who I could give it to. But life is so much more dynamic than that. Love doesn’t disappear when you give it away, and new love doesn’t make old love any less legitimate.

Ernest. Oh, I can't eat any more. Hans. Just this shining muscatelle! Ernest. My elasticity has its limit.

If you want to run faster, it’s hard to improve on the training haiku penned by Mayo Clinic physiologist Michael Joyner, the man whose 1991 journal paper foretold the two-hour-marathon chase: Run a lot of miles Some faster than your race pace Rest once in a while22

Attachment exerted an invisible but powerful pull on the child, just as heavenly bodies are connected by gravitational forces. But unlike gravity, attachment makes its presence known by a negative inverse square law: the further the attached person is from their secure base, the greater the pull of attachment. The 'elastic band' which constitutes the attachment bond is slack and imperceptible in the presence of a secure base. If the secure base becomes unreliable or the limits of exploration are reached, the bond tugs at the heartstrings.

If I could go back in time to alter the course of my own running career, after a decade of writing about the latest research in endurance training, the single biggest piece of advice I would give to my doubt-filled younger self would be to pursue motivational self-talk training—with diligence and no snickering.

At low speeds, the effort is primarily aerobic (meaning “with oxygen”), since oxygen is required for the most efficient conversion of stored food energy into a form your muscles can use. Your VO2max reflects your aerobic limits. At higher speeds, your legs demand energy at a rate that aerobic processes can’t match, so you have to draw on fast-burning anaerobic (“without oxygen”) energy sources.

I make no apology for this digression, especially as this is an introduction which all young people and those who never like to think (and it is a bad habit) will naturally skip. It seems to me very desirable that we should sometimes try to understand the limitations of our nature, so that we may not be carried away by the pride of knowledge. Man's cleverness is almost indefinite, and stretches like an elastic band, but human nature is like an iron ring. You can go round and round it, you can polish it highly, you can even flatten it a little on one side, whereby you will make it bulge out the other, but you will never, while the world endures and man is man, increase its total circumference. It is the one fixed unchangeable thing -- fixed as the stars, more enduring than the mountains, as unalterable as the way of the Eternal. Human nature is God's kaleidoscope, and the little bits of coloured glass which represent our passions, hopes, fears, joys, aspirations towards good and evil and what not, are turned in His mighty hand as surely and as certainly as it turns the stars, and continually fall into new patterns and combinations. But the composing elements remain the same, nor will there be one more bit of coloured glass nor one less for ever and ever.

His ignorance was as remarkable as his knowledge. Of contemporary literature, philosophy and politics he appeared to know next to nothing. Upon my quoting Thomas Carlyle, he inquired in the naivest way who he might be and what he had done. My surprise reached a climax, however, when I found incidentally that he was ignorant of the Copernican Theory and of the composition of the Solar System. That any civilized human being in this nineteenth century should not be aware that the earth travelled round the sun appeared to be to me such an extraordinary fact that I could hardly realize it. “You appear to be astonished,” he said, smiling at my expression of surprise. “Now that I do know it I shall do my best to forget it.” “To forget it!” “You see,” he explained, “I consider that a man’s brain originally is like a little empty attic, and you have to stock it with such furniture as you choose. A fool takes in all the lumber of every sort that he comes across, so that the knowledge which might be useful to him gets crowded out, or at best is jumbled up with a lot of other things so that he has a difficulty in laying his hands upon it. Now the skilful workman is very careful indeed as to what he takes into his brain-attic. He will have nothing but the tools which may help him in doing his work, but of these he has a large assortment, and all in the most perfect order. It is a mistake to think that that little room has elastic walls and can distend to any extent. Depend upon it there comes a time when for every addition of knowledge you forget something that you knew before. It is of the highest importance, therefore, not to have useless facts elbowing out the useful ones.” “But the Solar System!” I protested. “What the deuce is it to me?” he interrupted impatiently; “you say that we go round the sun. If we went round the moon it would not make a pennyworth of difference to me or to my work.” I was on the point of asking him what that work might be, but something in his manner showed me that the question would be an unwelcome one. I pondered over our short conversation, however, and endeavoured to draw my deductions from it. He said that he would acquire no knowledge which did not bear upon his object. Therefore all the knowledge which he possessed was such as would be useful to him. I enumerated in my own mind all the various points upon which he had shown me that he was exceptionally well-informed. I even took a pencil and jotted them down. I could not help smiling at the document when I had completed it. It ran in this way— SHERLOCK HOLMES—his limits. 1. Knowledge of Literature.—Nil. 2. Philosophy.—Nil. 3. Astronomy.—Nil. 4. Politics.—Feeble. 5. Botany.—Variable. Well up in belladonna, opium, and poisons generally. Knows nothing of practical gardening. 6. Geology.—Practical, but limited. Tells at a glance different soils from each other. After walks has shown me splashes upon his trousers, and told me by their colour and consistence in what part of London he had received them. 7. Chemistry.—Profound. 8. Anatomy.—Accurate, but unsystematic. 9. Sensational Literature.—Immense. He appears to know every detail of every horror perpetrated in the century. 10. Plays the violin well. 11. Is an expert singlestick player, boxer, and swordsman. 12. Has a good practical knowledge of British law.

We pass through vast halls, each with a capacity of ten Kronecker units, and creep like so many ants clinging to the folds of breathing vaults and craning to watch the flight of soaring girders, opalescent in the glare of searchlights, and elastic domes which criss-cross and balance each other unerringly, the perfection of a moment, since everything here passes and fades. The essence of this architecture is movement synchronized towards a precise objective. We observe a fraction of the process, like hearing the vibration of a single string in an orchestra of supergiants. We know, but cannot grasp, that above and below, beyond the limits of perception or imagination, thousands and millions of simultaneous transformations are at work, interlinked like a musical score by mathematical counterpoint. It has been described as a symphony in geometry, but we lack the ears to hear it.

Beneath a necessity thus almighty, what is artificial in man's life seems insignificant. He seems to take his task so minutely from intimations of Nature, that his works become as it were hers, and he is no longer free. But if we work within this limit, she yields us all her strength. All powerful action is performed by bringing the forces of nature to bear upon our objects. We do not grind corn or lift the loom by our own strength, but we build a mill in such position as to set the north wind to play upon our instrument, or the elastic force of steam, or the ebb and flow of the sea. So in our handiwork, we do few things by muscular force, but we place ourselves in such attitudes as to bring the force of gravity, that is, the weight of the planet, to bear upon the spade or the axe we wield. In short, in all our operations we seek not to use our own, but to bring a quite infinite force to bear.

We can stretch our personalities, but only up to a point. Our inborn temperaments influence us, regardless of the lives we lead. A sizable part of who we are is ordained by our genes, by our brains, by our nervous systems. And yet the elasticity that Schwartz found in some of the high-reactive teens also suggests the converse: we have free will and can use it to shape our personalities. These seem like contradictory principles, but they are not. Free will can take us far, suggests Dr. Schwartz’s research, but it cannot carry us infinitely beyond our genetic limits. Bill Gates is never going to be Bill Clinton, no matter how he polishes his social skills, and Bill Clinton can never be Bill Gates, no matter how much time he spends alone with a computer. We might call this the “rubber band theory” of personality. We are like rubber bands at rest. We are elastic and can stretch ourselves, but only so much.

Leadership obeys the principle of Hooke's law to the very bone. It explains: When an elastic material is stretched, it returns to its original position. But when it's over stretched beyond its limit point, it loses its elasticity and becomes plastic, and later cuts or breaks. As a leader, in your leadership disposition, it behoves of you to acquaint yourself with this very leadership principle that edges forward. It's however, a human nature to adopt to an environment, so, leaders are humans, they tend to have this rapore with their followers which is somewhat a must needed. But the ability for such one to return and recollect to knowing his boundary makes a good leader. A phenomenon whereby he becomes drunk of platitudes, then it comes to a time where they (followers) dictate for him. And even sought and suggest plans without his consent or knowing, it has gotten to the point of plastic and break respectively.

On another plane, only a brute in a state of irrational fury can imagine that men should be sadistically tortured in order to obtain their consent. Such an act only accomplishes the subjugation of one man by another, in an outrageous relationship between persons. The representative of rational totality is content, on the contrary, to allow the object to subdue the person in the soul of man. The highest mind is first of all reduced to the level of the lowest by the police technique of joint accusation. Then five, ten, twenty nights of insomnia will culminate an illusory conviction and will bring yet another dead soul into the world. From this point of view, the only psychological revolution known to our times since Freud's has been brought about by the NKVD and the political police in general. Guided by a determinist hypothesis that calculates the weak points and the degree of elasticity of the soul, these new techniques have once again thrust aside one of man's limits and have attempted to demonstrate that no individual psychology is original and that the common measure of all human character is matter. They have literally created the physics of the soul.

1 – Thinking Straight Maxim 1 - When you are having trouble getting your thinking straight, go to an extreme case Maxim 2 - When you are having trouble getting your thinking straight, go to a simple case Maxim 3 – Don’t take refuge in complexity Maxim 4 - When trying to understand a complex real-world situation, think of an everyday analogue 2 – Tackling Uncertainty Maxim 5 - The world is much more uncertain than you think Maxim 6 - Think probabilistically about the world Maxim 7 - Uncertainty is the friend of the status quo 3 – Making Decisions Maxim 8 - Good decisions sometimes have poor outcomes Maxim 9 - Some good decisions have a high probability of a bad outcome Maxim 10 - Errors of commission should be weighted the same as errors of omission Maxim 11 - Don’t be limited by the options you have in front of you Maxim 12 - Information is only valuable if it can change your decision 4 – Understanding Policy Maxim 13 - Long division is the most important tool for policy analysis Maxim 14 - Elasticities are a powerful tool for understanding many important things in life Maxim 15 - Heterogeneity in the population explains many phenomena Maxim 16 - Capitalize on complementarities

We also find *physics*, in the widest sense of the word, concerned with the explanation of phenomena in the world; but it lies already in the nature of the explanations themselves that they cannot be sufficient. *Physics* is unable to stand on its own feet, but needs a *metaphysics* on which to support itself, whatever fine airs it may assume towards the latter. For it explains phenomena by something still more unknown than are they, namely by laws of nature resting on forces of nature, one of which is also the vital force. Certainly the whole present condition of all things in the world or in nature must necessarily be capable of explanation from purely physical causes. But such an explanation―supposing one actually succeeded so far as to be able to give it―must always just as necessarily be burdened with two essential imperfections (as it were with two sore points, or like Achilles with the vulnerable heel, or the devil with the cloven foot). On account of these imperfections, everything so explained would still really remain unexplained. The first imperfection is that the *beginning* of the chain of causes and effects that explains everything, in other words, of the connected and continuous changes, can positively *never* be reached, but, just like the limits of the world in space and time, recedes incessantly and *in infinitum*. The second imperfection is that all the efficient causes from which everything is explained always rest on something wholly inexplicable, that is, on the original *qualities* of things and the *natural forces* that make their appearance in them. By virtue of such forces they produce a definite effect, e.g., weight, hardness, impact, elasticity, heat, electricity, chemical forces, and so on, and such forces remain in every given explanation like an unknown quantity, not to be eliminated at all, in an otherwise perfectly solved algebraical equation. Accordingly there is not a fragment of clay, however little its value, that is not entirely composed of inexplicable qualities. Therefore these two inevitable defects in every purely physical, i.e., causal, explanation indicate that such an explanation can be only *relatively* true, and that its whole method and nature cannot be the only, the ultimate and hence sufficient one, in other words, cannot be the method that will ever be able to lead to the satisfactory solution of the difficult riddles of things, and to the true understanding of the world and of existence; but that the *physical* explanation, in general and as such, still requires one that is *metaphysical*, which would furnish the key to all its assumptions, but for that very reason would have to follow quite a different path. The first step to this is that we should bring to distinct consciousness and firmly retain the distinction between the two, that is, the difference between *physics* and *metaphysics*. In general this difference rests on the Kantian distinction between *phenomenon* and *thing-in-itself*. Just because Kant declared the thing-in-itself to be absolutely unknowable, there was, according to him, no *metaphysics* at all, but merely immanent knowledge, in other words mere *physics*, which can always speak only of phenomena, and together with this a critique of reason which aspires to metaphysics." ―from_The World as Will and Representation_. Translated from the German by E. F. J. Payne. In Two Volumes, Volume II, pp. 172-173

A great deal of the talk about laissez faire [in the nineteenth century] must be discounted, or at least put into its proper context. In many cases the argument concealed an admission that a problem was insoluble, or that it must be endured, because no one could think of any method of solving it. From this point of view, the policy of laissez faire was not the result of a new and optimistic belief in the progress of society through private enterprise. It was rather an acknowledgement that the fund of skill and experience at the service of society was limited, and that, in the management of their common a airs, men would not be able to find the elasticity and adaptiveness [sic] which individuals showed in devising schemes for their own self-interest. e treatment of social and economic questions was more haphazard and empirical than Englishmen were ready to acknowledge. If a practical solution suggested itself, if a tentative experiment could be made, the doctrine of laissez faire would be thrust aside, only to be used again after another failure to discover the way out of a difficulty (Woodward, [1938] 1962 , p. 16).

Competition also was coming from a new trend in industry to finance future growth out of profits rather than from borrowed capital. This was the outgrowth of free-market interest rates which set a realistic balance between debt and thrift. Rates were low enough to attract serious borrowers who were confident of the success of their business ventures and of their ability to repay, but they were high enough to discourage loans for frivolous ventures or those for which there were alternative sources of funding—for example, one's own capital. That balance between debt and thrift was the result of a limited money supply. Banks could create loans in excess of their actual deposits, as we shall see, but there was a limit to that process. And that limit was ultimately determined by the supply of gold they held. Consequently, between 1900 and 1910, seventy per cent of the funding for American corporate growth was generated internally, making industry increasingly independent of the banks.12 Even the federal government was becoming thrifty. It had a growing stockpile of gold, was systematically redeeming the Greenbacks—which had been issued during the Civil War—and was rapidly reducing the national debt. Here was another trend that had to be halted. What the bankers wanted—and what many businessmen wanted also—was to intervene in the free market and tip the balance of interest rates downward, to favor debt over thrift. To accomplish this, the money supply simply had to be disconnected from gold and made more plentiful or, as they described it, more elastic.

Most American climbers, Twight argues, “are scared to be hungry, or they wouldn’t carry so much damn food.

Run a lot of miles Some faster than your race pace Rest once in a while22

Burke and others published a pair of studies in 2016 using a protocol dubbed “sleep low,” which involved a high-quality carbohydrate-fueled workout in the late afternoon, followed by a carbohydrate-free dinner; then, the next morning, a carbohydrate-depleted moderate workout before breakfast.38 Repeating this cycle just three times, for a total of six days, produced a 3 percent improvement in 20-kilometer cycling times.

In 2015, Staiano and Marcora presented recently declassified results from a military-funded study of thirty-five volunteers who had trained three times a week for an hour at a time on stationary bikes. Half of the volunteers did brain training while cycling, using the flashing-letters test that I had tried. After twelve weeks, the physical-training-only group had improved their time to exhaustion by 42 percent; in comparison the physical-plus-brain-training group had improved by a whopping 126 percent.

The degree of consciousness of a living creature fluctuates up and down, depending on its emotional condition, within the limits of an octave of vibrations. These fluctuations, however, must not exceed the limits of elasticity of the nerves; for if they do, injuries and sicknesses of a more or less serious nature occur, even death. The vibration belonging to creative vital energy is absolutely lethal for creatures whose consciousness has not yet reached this level. It would burn out the nerves and nervous centres. For this reason, vital energy from the spinal column, where it has its seat, is transformed into a low vibration corresponding to the degree of consciousness of the person concerned and only this transformed vital current is conducted into the body. ‘Thus animals, for example, are animated by a much lower life vibration than primitive man; and primitive man with his beast-like selfish nature, is animated by lower vibrations of vital energy than a person who is spiritually developed. If one were to conduct the vital energy of a highly developed human being into an animal or a much less developed human, the animal or “lower-level” human would die instantly because of the contact with the more powerful vibrations.

It was because these men, whatever their profession—philosopher, architect, lawyer, painter, doctor, artist and priest—were by force of the times they lived in soldiers also, and understood that speed and skill and toughness and above all self-confidence came from being pushed again and again and again past the edge of endurance until that limit became as elastic as an extra muscle, held in reserve.

Worryingly, they gained even more strength from imagining themselves doing an evil deed—confirmation, perhaps, of a theory, long discussed on online running message boards, that the best way to run an 800-meter race is fueled by “pure hate.

I tried to explain to her that every good race involved exceeding what felt like my physical limits. If I ran 800 meters as hard as I could in practice, I might run 2:10; in a race, I might run 1:55. Accessing that hidden reserve was anything but a foregone conclusion, and waiting to see how deep I would manage to dig was what made racing both exhilarating and terrifying. (I never did get a date with her.)

the preparation and resolution of a dis-c(5rd ; the transition from a point of rest to one of unrest, and thence to a new point of rest, which is one of the great underlying prmciples of musical art. Concords, and discords, and the sys-tematisation of tones into scales, are all inextricably mixed up together, and Debussy's departure from what has hitherto been the ordered procedure in relation to chords has involved a proportionate departure, or nearly so, as regards scales. This, again, it is possible to consider as an addition to, rather than a destruction of the proved resources of music. The universal employment of the major and minor modes exclusively, was born of expedience. They made for elasticity and security ; but at the same time the door was thereby closed upon the old Church modes, and with them, upon a range of effects which belonged to these old-world modes alone. Many of these effects Debussy has revived, but in this only treading more continuously in a path which has been adventured upon by various composers, from Beethoven to Weingartner. Not the construction of music, however, but its effect, is the main subject of consideration so far as the non-professional public is concerned. In this connection there are a few points which it will be worth while to consider with some little attention, for upon this consideration will it depend very much whether one takes a reasonable view, or the reverse, of Debussy's music. and the reverse, it should be mentioned, may equally well be laudatory or hostile ; adulation or detraction alike insufficiently informed. In the first place it is to be borne in mind that Debussy's music overrides a good many established theories, or rather the limitations within which the operation of these theories has hitherto been confined.

Stretch your limits once a while, lest you lose your elasticity

I grew up hearing my father digging into words for images that will stretch the limits of life for my siblings and me. In my father’s mouth, bitter, rigid words become sweet and elastic like taffy. His poetry shields us from the poverty of our lives.

Run a lot of miles Some faster than your race pace Rest once in a while

The Winning Mind Set, a 2006 self-help book by Jim Brault and Kevin Seaman, which uses Bannister’s four-minute mile as a parable about the importance of self-belief. “[W]ithin one year, 37 others did the same thing,” they write. “In the year after that, over 300 runners ran a mile in less than four minutes.” Similar larger-than-life (that is, utterly fictitious) claims are a staple in motivational seminars and across the Web: once Bannister showed the way, others suddenly brushed away their mental barriers and unlocked their true potential.

In 1865, for example, a pair of German scientists collected their own urine while hiking up the Faulhorn, an 8,000-foot peak in the Bernese Alps, then measured its nitrogen content to establish that protein alone couldn’t supply all the energy needed for prolonged exertion.

brain-altering drugs like Tylenol that boost endurance without any effect on the muscles or heart.23

The nation is imagined as limited because even the largest of them, encompassing perhaps a billion living human beings, has finite, if elastic, boundaries, beyond which lie other nations…

To prove it, Marcora and his colleagues tested a simple self-talk intervention—precisely the approach my teammates and I had laughed at two decades earlier. They had twenty-four volunteers complete a cycling test to exhaustion, then gave half of them some simple guidance on how to use positive self-talk before another cycling test two weeks later. The self-talk group learned to use certain phrases early on (“feeling good!”) and others later in a race or workout (“push through this!”), and practiced using the phrases during training to figure out which ones felt most comfortable and effective. Sure enough, in the second cycling test, the self-talk group lasted 18 percent longer than the control group, and their rating of perceived exertion climbed more slowly throughout the test. Just like a smile or frown, the words in your head have the power to influence the very feelings they’re supposed to reflect.

At low speeds, the effort is primarily aerobic (meaning “with oxygen”), since oxygen is required for the most efficient conversion of stored food energy into a form your muscles can use. Your VO2max reflects your aerobic limits. At higher speeds, your legs demand energy at a rate that aerobic processes can’t match, so you have to draw on fast-burning anaerobic (“without oxygen”) energy sources. The problem, as Hopkins and Fletcher had shown in 1907, is that muscles contracting without oxygen generate lactic acid. Your muscles’ ability to tolerate high levels of lactic acid—what we would now call anaerobic capacity—is the other key determinant of endurance, Hill concluded, particularly in events lasting less than about ten minutes.

This shows that simply getting fitter doesn’t magically increase your pain tolerance. How you get fit matters: you have to suffer.

Samuele Marcora, is that endurance is “the struggle to continue against a mounting desire to stop.

The mind, in other words, frames the outer limits of what we believe is humanly possible.

Our brains are sending signals to our muscles; as we fatigue, those signals are getting weaker and weaker,” Putrino explained. “The brain is making a choice. But the brain’s opinion isn’t always right.

endurance is “the struggle to continue against a mounting desire to stop.”5 That’s

Without a time machine (and a rectal probe), it’s impossible to settle the debate one way or the other—but we can rule out heatstroke.

In the end, the most effective limit-changers are still the simplest—so simple that we’ve barely mentioned them. If you want to run faster, it’s hard to improve on the training haiku penned by Mayo Clinic physiologist Michael Joyner, the man whose 1991 journal paper foretold the two-hour-marathon chase: Run a lot of miles Some faster than your race pace Rest once in a while22

When you exercise repeatedly in hot conditions, your body’s protective responses get progressively better: you sweat more heavily, starting at a lower temperature; your vessels dilate even wider to deliver heat-laden blood to the skin; and the total volume of blood in your body increases, allowing your heart rate to stay lower during exercise.

Their conclusion was that “the end point of any performance is never an absolute fixed point but rather is when the sum of all negative factors such as fatigue and muscle pain are felt more strongly than the positive factors of motivation and will power.

Under normal circumstances, it’s very rare for people to reach the limits of their cold tolerance if they’re appropriately dressed,

If you can fill the unforgiving minute With sixty seconds’ worth of distance run, Yours is the Earth and everything that’s in it.

But Landy’s enigma isn’t that he wasn’t quite good enough. It’s that he clearly was.

sprint fearlessly to an enormous early lead in the women’s 1,500, click off lap after metronomic lap all alone,

Suddenly my obsessive calculating and endless strategizing seemed ridiculous and overwrought. I was here to run a race; why not just run as hard as I could?

at least in recreational athletes, pain tolerance is both a trainable trait and a limiting factor in endurance.

psychology

And every machine, no matter how great, has a maximum capacity. Worsley, in trying to cross Antarctica on his own, had embarked on a mission that exceeded his body’s capacity, and no amount of mental strength and tenacity could change that calculation.

By the time I ran what would turn out to be my fastest 5,000, on a perfect evening in Palo Alto, California, in 2003, I’d decided I needed a new mental strategy: I would pretend I was only running 4,000 meters, and simply not worry if I had to jog the last kilometer. I wanted to run 2:45 per kilometer, and my first three kilometers were 2:45, 2:45, 2:47. The moment of truth: I knuckled down and vowed to run the fourth kilometer as hard as I could—but little by little, I drifted back from the pack I was running with.

Other LSD analogs Numerous other “research chemical” analogs of LSD offer comparable dosage and effect profiles. They include AL-LAD, ALD-52, ETH-LAD, PRO-LAD, and LSZ. Anecdotal reports list alertness, clarity, mood enhancement, and cognitive elasticity among their effects when microdosed. Some users even prefer these analogs to LSD. In some countries, however, their legal status can be iffy. As with 1P-LSD, possession in the U.S. may or may not be prosecuted under the Federal Analogue Act; the law itself is ambiguously worded and case law is limited.

enduring the rack rather than submitting to the guillotine