人的肌肉（KG）（【类似原文】）V1：
考了一篇第一段说传统观点说人的肌肉劳累是因为肌肉的什么酸acid增加了
第二段说但是现在加拿大的一票科学家说运动员劳累的时候这个酸没有增加啊,还有一个地方的科学家(好象是北非的,很神奇)也举出了反例.
最后一段说什么传统的观点说的酸增加确实对了但是地方不对.然后用计算机证明再解释了一通.
问题考了一个是最后一段的作用,这是我的最后一篇了没大有时间看了.
V2：（710）
Theory 1: muscles go into automated brake when lactic acid builds up after exhausting exercise, leading to fatigue.
Theory Two: psychologists argue central nervous system controls the sense of extreme fatigue to keep body from collapse; psychologists say that theory 1 is right about lactic build up, however wrong in the "location".( location=Central nervous system)
V3：（V 40）
第一段：1922年有个诺贝尔的理论，人劳累，是因为肌肉释放的酸达到极限，从而让肌肉休息。
第二段：加拿大的科学家有异议。而南非的科学家取出反例，在一种特定的情况下（这种情况可以导致肌肉释放的酸不会大幅增加），对运动员研究发现他们疲劳的时候酸的含量很低，30%的肌肉已经休息了。虽然这些运动员说他们已经很累，达到极限了。
第三段：科学家们就提出假设来解决这个问题，指出1922年有个诺贝尔的理论是部分正确的。但是人的劳累其实不是客观事实，而是人的主观情绪。然后这个理论还能够解释部分现象。
类似原文：By pipilovelail
注意highlight的部分
Interestingly — or unnervingly, depending on how you look at it — some researchers are uncovering evidence that Stanovnik’s rule of thumb might be right. A spate of recent studies has contributed to growing support for the notion that the origins and controls of fatigue lie partly, if not mostly, within the brain and the central nervous system. The new research puts fresh weight to the hoary coaching cliché: you only think you’re tired.From the time of Hippocrates, the limits of human exertion were thought to reside in the muscles themselves, a hypothesis that was established in 1922 with the Nobel Prize-winning work of Dr. A.V. Hill. The theory went like this: working muscles, pushed to their limit, accumulated lactic acid. When concentrations of lactic acid reached a certain level, so the argument went, the muscles could no longer function. Muscles contained an ‘‘automatic brake,’’ Hill wrote, ‘‘carefully adjusted by nature.’’Researchers, however, have long noted a link between neurological disorders and athletic potential. In the late 1800’s, the pioneering French doctor Philippe Tissié observed that phobias and epilepsy could be beneficial for athletic training. A few decades later, the German surgeon August Bier measured the spontaneous long jump of a mentally disturbed patient, noting that it compared favorably to the existing world record. These types of exertions seemed to defy the notion of built-in muscular limits and, Bier noted, were made possible by ‘‘powerful mental stimuli and the simultaneous elimination of inhibitions.’’Questions about the muscle-centered model came up again in 1989 when Canadian researchers published the results of an experiment called Operation Everest II, in which athletes did heavy exercise in altitude chambers. The athletes reached exhaustion despite the fact that their lactic-acid concentrations remained comfortably low. Fatigue, it seemed, might be caused by something else.In 1999, three physiologists from the University of Cape Town Medical School in South Africa took the next step. They worked a group of cyclists to exhaustion during a 62-mile laboratory ride and measured, via electrodes, the percentage of leg muscles they were using at the fatigue limit. If standard theories were true, they reasoned, the body should recruit more muscle fibers as it approached exhaustion — a natural compensation for tired, weakening muscles.Instead, the researchers observed the opposite result. As the riders approached complete fatigue, the percentage of active muscle fibers decreased, until they were using only about 30 percent. Even as the athletes felt they were giving their all, the reality was that more of their muscles were at rest. Was the brain purposely holding back the body?‘‘It was as if the brain was playing a trick on the body, to save it,’’ says Timothy Noakes, head of the Cape Town group. ‘‘Which makes a lot of sense, if you think about it. In fatigue, it only feels like we’re going to die. The actual physiological risks that fatigue represents are essentially trivial.’’From this, Noakes and his colleagues concluded that A.V. Hill had been right about the automatic brake, but wrong about its location. They postulated the existence of what they called a central governor: a neural system that monitors carbohydrate stores, the levels of glucose and oxygen in the blood, the rates of heat gain and loss, and work rates. The governor’s job is to hold our bodies safely back from the brink of collapse by creating painful sensations that we interpret as unendurable muscle fatigue.Fatigue, the researchers argue, is less an objective event than a subjective emotion — the brain’s clever, self-interested attempt to scare you into stopping. The way past fatigue, then, is to return the favor: to fool the brain by lying to it, distracting it or even provoking it. (That said, mental gamesmanship can never overcome a basic lack of fitness. As Noakes says, the body always holds veto power.)‘‘Athletes and coaches already do a lot of this instinctively,’’ Noakes says. ‘‘What is a coach, after all, but a technique for overcoming the governor?’’The governor theory is far from conclusive, but some scientists are focusing on a walnut-size area in the front portion of the brain called the anterior cingulate cortex. This has been linked to a host of core functions, including handling pain, creating emotion and playing a key role in what’s known loosely as willpower. Sir Francis Crick, the co-discoverer of DNA, thought the anterior cingulate cortex to be the seat of the soul. In the sports world, perhaps no soul relies on it more than Jure Robic’s.Some people ‘‘have the ability to reprocess the pain signal,’’ says Daniel Galper, a senior researcher in the psychiatry department at the University of Texas Southwestern Medical Center at Dallas. ‘‘It’s not that they don’t feel the pain; they just shift their brain dynamics and alter their perception of reality so the pain matters less. It’s basically a purposeful hallucination.’’Noakes and his colleagues speculate that the central governor theory holds the potential to explain not just feats of stamina but also their opposite: chronic fatigue syndrome (a malfunctioning, overactive governor, in this view). Moreover, the governor theory makes evolutionary sense. Animals whose brains safeguarded an emergency stash of physical reserves might well have survived at a higher rate than animals that could drain their fuel tanks at will.The theory would also seem to explain a sports landscape in which ultra-endurance events have gone from being considered medically hazardous to something perilously close to routine. The Ironman triathlon in Hawaii — a 2.4-mile swim, 112-mile bike ride and marathon-length run — was the ne plus ultra in endurance in the 1980’s, but has now been topped by the Ultraman, which is more than twice as long. Once obscure, the genre known as adventure racing, which includes 500-plus-mile wilderness races like Primal Quest, has grown to more than 400 events each year. Ultramarathoners, defined as those who participate in running events exceeding the official marathon distance of 26.2 miles, now number some 15,000 in the United States alone. The underlying physics have not changed, but rather our sense of possibility. Athletic culture, like Robic, has discovered a way to tweak its collective governor.
考古：
版本1
| p1, 老观点，肌肉运动后会产大量acid，新观点，不是这样的p2, 新的实验发现cylist运动了一段时间，没有增加acid?,反而减少了，与老观点不符p3,另一个例子，记不清了，然后结论是运动是由大脑主观调节的。
|
[tr][td=576]版本2
[/td][/tr][tr][td=576]p1, 老观点，肌肉运动后会产大量acid，新观点，不是这样的
p2, 两个实验：第一个是canada的（有题），第二个是新的实验发现cylist运动了一段时间，没有增加acid?,反而减少了，与老观点不符
p3,另一个例子，记不清了，然后结论是运动是由大脑主观调节的。---评价了老观点和新试验，提出一种model，说老观点有部分是对的，但是老观点里关于作用产生的位置错了
[/td][/tr][tr][td=576]版本3
[/td][/tr][tr][td=576]第一段，1920诺贝尔奖获得者提出理论疲劳时因为肌肉里的某个酸堆积造成的，第二段，现在观察证明不对，因为给运动员吃了什么东西完全不起作用，还是 累。第三段：说明了应该是大脑控制疲劳。1920的理论说的酸的积累并不在肌肉里。当什么累积的时候大脑就觉得累了，给人信号说累了。
问题，main idea。如果人要控制疲劳那么应该怎么做，我选的是训练自己，让自己对疲劳没感觉。
[/td][/tr]
以下考古 By XYXB
V1
流行的理论是一种acid的累计，会让人有brake (大概是什么跑到一定距离觉得跑不动了，跑跑又ok了的极限吧，忘记中文是什么=。=)
但是加拿大的科学家对跳高运动员研究发现他们疲劳的时候acid的含量很低，然后另一国的专家发现理论上讲部分肌肉累的时候，人应该利用起别的肌肉，但实际上别的肌肉这时候在休息
然后说一种新的理论解释这个问题，说是神经系统为了保护人from collapse, 这种疲劳是主管感觉而不是客观现象
V2
第一段，1922年有个诺贝尔大牛有个理论，说肌肉释放的什么酸是自动刹车，让肌肉休息。第二段，1989年加拿大的哥们有小异议，是补充理论，1999，南非三个哥们有新发现（主要内容）。第二段论证南非哥们的理论内容和原理。
第三段，总结他们的观点，有他们对1922年理论的评价，部分对，但没有指出，肌肉组织其实不是客观事实，而是受大脑操控的主观情绪影响，这才作用的。 |
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发表于 2011-1-2 01:14:53
