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Strength or endurance: A question of muscle
Acta Histochemica 117 (2015) 1–3
Contents lists available at ScienceDirect
Acta Histochemica journal homepage: www.elsevier.de/acthis
Editorial
Strength or endurance: A question of muscle
Primitive man As far as is known our earliest ancestors in Africa lived by hunting wild prey in the primeval forests and evolved to run long distances. This involved extensive treks, speed of the chase and endurance, which were essential features for survival and feeding the family. This may explain why the best long distance runners today are of African origin. However, the best hunters, who were skinny, fleet of foot and capable of endurance activities had even in ancient times to compete with muscular brawn, where the largest, strongest and most muscular individuals were physical warriors who led the tribe in combat and also had the first choice of the most attractive females. This may explain why many young males today visit the gym to perform weight-bearing exercises to build muscle mass, which they believe will impress the females, regardless of how distorted their body bulk appears. In vertebrates these features are still evident with many species, such as the migrating birds that possess incredible endurance in contrast with other avian species that are very muscular, heavy, lethargic and cumbersome.
Sports in ancient times Running and racing feature in classical literature. The earliest recorded running death occurred in Greece in 490 BC. The unfortunate Pheidippides expired moments after delivering the momentous news of the Battle of Marathon that Athens had defeated Darius’ forces. It is not clear if his demise resulted from a lack of preparatory training (running 150 miles in two days) or the stress of bearing the exciting news. Possibly the endorphins and euphoria generated by the bearer of such an exclusive message were sufficient stimulus to propel him to the finish line, but lack of physiological fitness led to his premature extinction. His final ejaculation, “Nike” (also the name of the goddess of victory), later provided a great brand-name for running shoes. Fortunately the modern marathon is much shorter and remains the only nonmetric race in modern athletics. The unusual distance (26 miles and 385 yards) was determined in the UK Olympics of 1908 with the marathon race from Windsor to London so that Queen Alexandra could get a prime view of the event. Ancient sports pitted man against man (or to be politically correct, person against person) in a battle for supremacy and victory. I do not know if David’s defeat of Goliath in Biblical times should be recorded as a fair sporting event. Against all odds the outcome was highly unexpected and provided insight that despite enormous http://dx.doi.org/10.1016/j.acthis.2014.10.006 0065-1281/© 2014 Elsevier GmbH. All rights reserved.
disparity in physical dimensions, mental preparation, practice and subterfuge can play important roles in sporting challenges. Sports were popular in ancient Greece judging from surviving statues and artistic depictions of young naked males displaying their physical prowess and skills in competitive athletic events. Common games of the period involving strength that have survived today include javelin and discus throwing. The aggressive combat sports, such as wrestling and boxing, have remained very popular spectator events even today though the “rings” evolved into squares. The period of ancient Greco-Roman games contributed several words for sporting gatherings: circus, theatre, stadium, arena and hippodrome. The ancient Romans greatly enjoyed the spectacle of competitive sporting events, even if the combatants faced very unfavorable odds. The losers of gladiatorial contests typically received a “thumbs-down” death sentence, whereas the more spectacular and entertaining bouts between gladiators and lions had even lower odds of survival. The massive stadia (such as the Colosseum in Rome) and the hippodromes for competitive horse and chariot racing are measures of the enormous popularity of these so-called sporting and often cruel spectacles. The bullfights of the Iberian Peninsula took a different sporting approach pitting man against bulls, though they skewed things to ensure that the odds favored the matadors. Whereas sports were largely restricted to males, it would be unfair to dismiss the amazing physical and athletic attributes of the Amazons, the all-female warriors of that classical period, who reputedly sacrificed a breast to facilitate archery. Although there are indications of organized competitive games in other ancient cultures, such as can be deduced from the surviving Mayan hoops and games fields in Yucatan ruins, most organized competitive team games, such as rugby and soccer, came much later. The myth persists that Dr. Thomas Arnold, the famed headmaster of Rugby School, an all-male English elitist and prestigious boarding school, introduced team games to the school curriculum in the mid-19th Century to encourage “athletic chivalry” and to allow pupils to release their aggressive adolescent energies on the playing fields rather than in the dormitories.
Modern athletic games Sporting events really took off with the reestablishment of the modern Olympic Games in Greece in 1898 and for the last century we have witnessed nations battling each other for honors in the sports arena. Athletics and track achievements, especially if world
2
Editorial / Acta Histochemica 117 (2015) 1–3
records are broken, are still regarded as the supreme events of the Olympics and receive the highest acclaim and publicity reflected in the Latin motto “Citius, Altius, Fortius”. Hitler in the 1936 Berlin Olympics was defeated in his attempts to prove Aryan racial superiority. Only at a later period, out of purely commercial interests, were the Olympics rejuvenated when they were thrown open to professional sportspeople rather than restricted to amateurs. It is axiomatic that all successful Olympic athletes are freaks located at very extremes of Gaussian curves. In no measure can any of these superhuman athletes be regarded as “normal”. Major athletic or sporting events such as the Olympics pit freak against freak mimicking to a degree the freaks displayed in the traveling circus or country fair, which included midgets, giants, strongmen, bearded ladies, and hyperflexible acrobats. Most professional basketball players are abnormal giants well exceeding 2 m height (head and shoulders taller than the average), who probably had greatly elevated growth hormone levels as adolescents giving them unfair advantage. Female gymnasts in contrast are typically preadolescent, undersized, underweight, anorexic girls, lacking breasts or menstrual cycles. Questions of gender It now seems hard to believe that the Olympics did not feature a women’s marathon until 1984 as the common accepted belief until then was that women should not run long distances for medical reasons! Other sports were only later open to women. The IAAF recognized the women’s pole vault only in 1992. Some of the female games, such as beach volleyball, have become highly popular voyeuristic events drawing enormous TV ratings. Science has to a degree solved several of the problematic issues of competitive sport including that of questionable gender. The introduction of cytogenetic analysis ended the era of East European masculine-phenotypes dominating female track and field events, though even today there are still questionable issues. In 1968 gender tests were made compulsory at Olympics events following the discovery that a Polish sprinter with gold and bronze awards (Eva Klobubowska) possessed a male chromosome. This was subsequently regarded as an unjust decision as she had an XXY genetic mutation (and technically could give birth). Even today questions of gender still are an issue and suspicions can blight successful athletes such as the South African middle-distance runner, Caster Semanya, who is one of 0.1% of women without the typical female XX genotype and has had to suffer unfair discrimination over her genetic condition, which many competing athletes feel gives her an unfair sporting advantage. The only Olympic events that are gender indifferent are the equestrian games, possibly because the performance depends to a large degree on the equine physical characteristics and performance rather than the rider. The best jockey mounted on a poor untalented nag will invariably be a recipe for a poor finish. Muscle typing and heterogeneity Our understanding of skeletal muscle physiology has helped contribute to improved performance in many sporting events. Enzyme cytochemistry has enabled analysis of skeletal muscle fiber typing. On a fairly simplistic basis we can divide muscle fibers into three main categories: type I, slow-twitch high oxidative, type IIb, fast-twitch low oxidative and an intermediate fiber type IIa. The mitochondria rich type I fibers are favored by endurance athletes such as marathon runners or long-distance cyclists, whereas the type IIb fibers use a more anaerobic (glycolytic) metabolism and are favored by short distance runners for generating short bursts of speed, though these fatigue rapidly. Sprinters develop fast-twitch
muscles (about 80%) which fatigue quickly, whereas marathon runners develop the slow-twitch muscles (about 80%). The physical make-up of these two types of athletes are completely different; whereas the sprinter needs well developed muscle mass for short bursts of energy, the long distance runner has relatively poorly developed muscles and a much smaller and lighter physique. The training exercises and preparation for these two different types of running are also completely different. It is now known that it is possible to use training regimens to transform fiber types, either for endurance or short bursts of speed. Body physique plays a major role in the type of running. A tall or heavy muscular person has a major advantage in competitive sprinting, whereas such a physique has no real chance in long distance running or endurance sports such as long distance cycling. The situation is more complicated for participants in the triathlon, who need to swim, cycle and run. The body and muscle physique best adapted for endurance running and cycling is not good for swimming. Perhaps the supreme athlete and the one deserving the greatest admiration is the all-rounder exemplified by the victor of the decathlon for men or the heptathlon for women. These involve a wide range of different athletic events. These supreme athletes surely must be equivalent to the garlanded victors of ancient Rome or Greece. Much of the research on different forms of exercise and muscle development has been done with rodents. Recently a mouse type has been developed leading to “mighty mice” in which there is a switch to increased numbers of type I fibers. These engineered mice are capable of continuous endurance running on a treadmill of up to twice that of their wild-type littermates. Fortunately we have not yet reached the stage where human engineering of muscle is practicable or ethical. Breaking records – Have we reached the limits? The sprinter Usain Bolt holds the world 100 m world record at 9.58 s. Since Jim Hines broke the 10 s barrier in 1968, the world record time has only improved by a meager 3.7% despite expanding knowledge in weight training, fitness, nutrition and technological advances in tracks and footwear. We still do not have a clear explanation of why the best sprinters mainly come from the West Indies. Beating the system Chemical substances to enhance physique and physiological performance are now likely to be detected even in trace amounts in urine and blood samples including abnormal levels of hormones secreted naturally in the body, such as erythropoietin. Athletes need to think twice before taking anabolic steroids, painkillers, cold-relief tablets, or even drinking too much coffee. When records are broken, there is always a cloud of suspicion that performance enhancing drugs may have played a part. Many athletes still try and beat the system. It is acceptable to improve your hematocrit by training in oxygen depleted sites such as Mexico City (provided the industrial pollution does not affect you). It is not acceptable to have blood taken, stored and returned to the body just before a sporting event (autologous transfusion). There are now new tests to determine autologous transfusion or use of human growth hormone. These tests range from mass spectroscopy to proteomics. However, unethical athletes continually manage to be one step ahead of the scientific detection for doping. The latest fad includes exposure to xenon or argon gases, which are apparently able to increase production of erythrocytes, possibly by increasing internal production of hypoxia inducible factor 1 (HIF-1) leading to enhanced secretion of erythropoietin (EPO). The world anti-doping agencies are
Editorial / Acta Histochemica 117 (2015) 1–3
banning use of xenon and argon by athletes, but there is still no valid test to detect use of these noble gases. Exercise can damage your health Chronic exercise can result in major physical changes to the body. In the general population, an enlarged heart is commonly a sign of a serious physiological or pathological problem. However, athletes as a result of their intensive training regimes frequently develop cardiac hypertrophy, which is anything but normal. If you examine an athlete’s heart test, you know right away that it is abnormal. They have enlarged hearts that have increased in volume to adapt to their training method. Many Tour de France riders have developed hearts 40% bigger than normal – for strength, stamina, and endurance. Epidemiological data reveal that top class athletes, at the peak of human fitness, do not have a lifespan that differs from the non-active population. On the contrary, sports induced injuries (e.g. joint cartilage in runners, or brain injuries in boxers) are likely to impair general physical well-being when the sport is no longer practiced. Moreover, there is considerable circumstantial evidence that regular or intensive exercise can damage health. Since the early 1970s it has been recorded that chronic exercise is linked to impaired immunity. Not only does exercise not help ward off disease, but it would appear that the opposite is in fact the case. During most bouts of strenuous exercise, the number of neutrophils increases dramatically resulting in a major increase in white blood cell count (similar to that occurring during acute phases of an inflammatory response). This has been explained in part by the increased stress imposed by chronic exercise or competitive events having a deleterious effect on the thymus gland. There is increasing evidence that strenuous exercise increases endogenous release of stress hormones such as the glucocorticoids and also epinephrine (adrenaline). At the end of bouts of exercise the cortisol and epinephrine levels in the blood can be up to 15 times that of normal. Chronic or excessive exercise can have long-term deleterious health consequences. Runners enormously increase their chances of developing irreversible joint cartilage damage. Ask any longdistance runner why they devote so much time, energy and suffering to running, and the reply is usually that they cannot do without it. The satisfaction of challenge and the flush of endorphins accompanying exhausting exercise are compulsive and if they are ill or injured and unable to jog or run, they may fall into deep depression. It is probably anthropomorphic to declare that laboratory rodents appear to enjoy exercise, however this can be surmised. Caged rats and mice with free access to an exercise wheel willingly jog for extended periods without any additional encouragement. Researchers using rodents know that successful experimental exercise endurance studies, such as treadmill running, require gradual acclimatization and a progressive period of training before the
3
studies can be undertaken. This is also true for humans, without adequate training programs and acclimatization before extensive physical exertion, there is increased chance of physical damage to various systems, which can even be fatal. Most athletes reach their peak achievements before the age of 25 after which they lose their competitive edge owing to aging processes. With normal human aging there is a steady decline in strength and muscle weakness with loss of up to 40% of muscle mass (“sarcopenia”) in the elderly though regular mild exercise and good diet can help defer this muscle decline. Selection for sporting success Several large countries, including the former Soviet Bloc countries and China, aim for the pinnacle of the medals table at the Olympic Games and have established specialized sport academies with very early selection of potential sports talent. They are cultivating personalized genomics even involving preschool children, who are given intensive training over many years. In the West, it is more usual for scouts to discover talent at a much later age. Sometimes this can be at the expense of a normal education and lifestyle (e.g. the College Basketball system in the USA seeks abnormally tall and talented teenagers). Accepting the fact that successful competitive athletes are physical freaks means that countries with the largest population of freaks to select from will continue to dominate the Olympic winners’ podium. Why should a dream team of giants dominate basketball games just because they are freakishly tall? We could of course try to level the playing field by adopting some rules of horseracing and introduce handicaps in athletics and games to help reduce the odds. This is unlikely to happen as long as we remain fascinated by the abnormal such as the modern Goliaths and Titans, the circus strongmen or acrobats. Why else does the Guinness Book of Records remain a perennial bestseller or why do couch potatoes in such large numbers continue to be glued to television broadcasts of the greatest sporting freak shows on the planet. Fortunately extensive TV coverage (now in widescreen HD) of the major sporting events allows voyeurs and couch potatoes to experience in closeup the trials and tribulations of our modern day warriors and freaks in the arena. Raymond Coleman Acta histochemica, Department of Anatomy and Cell Biology, Rappaport Faculty of Medicine, Technion – Israel Institute of Technology, PO Box 9649, Haifa 31096, Israel E-mail address: [email protected] 16 October 2014
Contents lists available at ScienceDirect
Acta Histochemica journal homepage: www.elsevier.de/acthis
Editorial
Strength or endurance: A question of muscle
Primitive man As far as is known our earliest ancestors in Africa lived by hunting wild prey in the primeval forests and evolved to run long distances. This involved extensive treks, speed of the chase and endurance, which were essential features for survival and feeding the family. This may explain why the best long distance runners today are of African origin. However, the best hunters, who were skinny, fleet of foot and capable of endurance activities had even in ancient times to compete with muscular brawn, where the largest, strongest and most muscular individuals were physical warriors who led the tribe in combat and also had the first choice of the most attractive females. This may explain why many young males today visit the gym to perform weight-bearing exercises to build muscle mass, which they believe will impress the females, regardless of how distorted their body bulk appears. In vertebrates these features are still evident with many species, such as the migrating birds that possess incredible endurance in contrast with other avian species that are very muscular, heavy, lethargic and cumbersome.
Sports in ancient times Running and racing feature in classical literature. The earliest recorded running death occurred in Greece in 490 BC. The unfortunate Pheidippides expired moments after delivering the momentous news of the Battle of Marathon that Athens had defeated Darius’ forces. It is not clear if his demise resulted from a lack of preparatory training (running 150 miles in two days) or the stress of bearing the exciting news. Possibly the endorphins and euphoria generated by the bearer of such an exclusive message were sufficient stimulus to propel him to the finish line, but lack of physiological fitness led to his premature extinction. His final ejaculation, “Nike” (also the name of the goddess of victory), later provided a great brand-name for running shoes. Fortunately the modern marathon is much shorter and remains the only nonmetric race in modern athletics. The unusual distance (26 miles and 385 yards) was determined in the UK Olympics of 1908 with the marathon race from Windsor to London so that Queen Alexandra could get a prime view of the event. Ancient sports pitted man against man (or to be politically correct, person against person) in a battle for supremacy and victory. I do not know if David’s defeat of Goliath in Biblical times should be recorded as a fair sporting event. Against all odds the outcome was highly unexpected and provided insight that despite enormous http://dx.doi.org/10.1016/j.acthis.2014.10.006 0065-1281/© 2014 Elsevier GmbH. All rights reserved.
disparity in physical dimensions, mental preparation, practice and subterfuge can play important roles in sporting challenges. Sports were popular in ancient Greece judging from surviving statues and artistic depictions of young naked males displaying their physical prowess and skills in competitive athletic events. Common games of the period involving strength that have survived today include javelin and discus throwing. The aggressive combat sports, such as wrestling and boxing, have remained very popular spectator events even today though the “rings” evolved into squares. The period of ancient Greco-Roman games contributed several words for sporting gatherings: circus, theatre, stadium, arena and hippodrome. The ancient Romans greatly enjoyed the spectacle of competitive sporting events, even if the combatants faced very unfavorable odds. The losers of gladiatorial contests typically received a “thumbs-down” death sentence, whereas the more spectacular and entertaining bouts between gladiators and lions had even lower odds of survival. The massive stadia (such as the Colosseum in Rome) and the hippodromes for competitive horse and chariot racing are measures of the enormous popularity of these so-called sporting and often cruel spectacles. The bullfights of the Iberian Peninsula took a different sporting approach pitting man against bulls, though they skewed things to ensure that the odds favored the matadors. Whereas sports were largely restricted to males, it would be unfair to dismiss the amazing physical and athletic attributes of the Amazons, the all-female warriors of that classical period, who reputedly sacrificed a breast to facilitate archery. Although there are indications of organized competitive games in other ancient cultures, such as can be deduced from the surviving Mayan hoops and games fields in Yucatan ruins, most organized competitive team games, such as rugby and soccer, came much later. The myth persists that Dr. Thomas Arnold, the famed headmaster of Rugby School, an all-male English elitist and prestigious boarding school, introduced team games to the school curriculum in the mid-19th Century to encourage “athletic chivalry” and to allow pupils to release their aggressive adolescent energies on the playing fields rather than in the dormitories.
Modern athletic games Sporting events really took off with the reestablishment of the modern Olympic Games in Greece in 1898 and for the last century we have witnessed nations battling each other for honors in the sports arena. Athletics and track achievements, especially if world
2
Editorial / Acta Histochemica 117 (2015) 1–3
records are broken, are still regarded as the supreme events of the Olympics and receive the highest acclaim and publicity reflected in the Latin motto “Citius, Altius, Fortius”. Hitler in the 1936 Berlin Olympics was defeated in his attempts to prove Aryan racial superiority. Only at a later period, out of purely commercial interests, were the Olympics rejuvenated when they were thrown open to professional sportspeople rather than restricted to amateurs. It is axiomatic that all successful Olympic athletes are freaks located at very extremes of Gaussian curves. In no measure can any of these superhuman athletes be regarded as “normal”. Major athletic or sporting events such as the Olympics pit freak against freak mimicking to a degree the freaks displayed in the traveling circus or country fair, which included midgets, giants, strongmen, bearded ladies, and hyperflexible acrobats. Most professional basketball players are abnormal giants well exceeding 2 m height (head and shoulders taller than the average), who probably had greatly elevated growth hormone levels as adolescents giving them unfair advantage. Female gymnasts in contrast are typically preadolescent, undersized, underweight, anorexic girls, lacking breasts or menstrual cycles. Questions of gender It now seems hard to believe that the Olympics did not feature a women’s marathon until 1984 as the common accepted belief until then was that women should not run long distances for medical reasons! Other sports were only later open to women. The IAAF recognized the women’s pole vault only in 1992. Some of the female games, such as beach volleyball, have become highly popular voyeuristic events drawing enormous TV ratings. Science has to a degree solved several of the problematic issues of competitive sport including that of questionable gender. The introduction of cytogenetic analysis ended the era of East European masculine-phenotypes dominating female track and field events, though even today there are still questionable issues. In 1968 gender tests were made compulsory at Olympics events following the discovery that a Polish sprinter with gold and bronze awards (Eva Klobubowska) possessed a male chromosome. This was subsequently regarded as an unjust decision as she had an XXY genetic mutation (and technically could give birth). Even today questions of gender still are an issue and suspicions can blight successful athletes such as the South African middle-distance runner, Caster Semanya, who is one of 0.1% of women without the typical female XX genotype and has had to suffer unfair discrimination over her genetic condition, which many competing athletes feel gives her an unfair sporting advantage. The only Olympic events that are gender indifferent are the equestrian games, possibly because the performance depends to a large degree on the equine physical characteristics and performance rather than the rider. The best jockey mounted on a poor untalented nag will invariably be a recipe for a poor finish. Muscle typing and heterogeneity Our understanding of skeletal muscle physiology has helped contribute to improved performance in many sporting events. Enzyme cytochemistry has enabled analysis of skeletal muscle fiber typing. On a fairly simplistic basis we can divide muscle fibers into three main categories: type I, slow-twitch high oxidative, type IIb, fast-twitch low oxidative and an intermediate fiber type IIa. The mitochondria rich type I fibers are favored by endurance athletes such as marathon runners or long-distance cyclists, whereas the type IIb fibers use a more anaerobic (glycolytic) metabolism and are favored by short distance runners for generating short bursts of speed, though these fatigue rapidly. Sprinters develop fast-twitch
muscles (about 80%) which fatigue quickly, whereas marathon runners develop the slow-twitch muscles (about 80%). The physical make-up of these two types of athletes are completely different; whereas the sprinter needs well developed muscle mass for short bursts of energy, the long distance runner has relatively poorly developed muscles and a much smaller and lighter physique. The training exercises and preparation for these two different types of running are also completely different. It is now known that it is possible to use training regimens to transform fiber types, either for endurance or short bursts of speed. Body physique plays a major role in the type of running. A tall or heavy muscular person has a major advantage in competitive sprinting, whereas such a physique has no real chance in long distance running or endurance sports such as long distance cycling. The situation is more complicated for participants in the triathlon, who need to swim, cycle and run. The body and muscle physique best adapted for endurance running and cycling is not good for swimming. Perhaps the supreme athlete and the one deserving the greatest admiration is the all-rounder exemplified by the victor of the decathlon for men or the heptathlon for women. These involve a wide range of different athletic events. These supreme athletes surely must be equivalent to the garlanded victors of ancient Rome or Greece. Much of the research on different forms of exercise and muscle development has been done with rodents. Recently a mouse type has been developed leading to “mighty mice” in which there is a switch to increased numbers of type I fibers. These engineered mice are capable of continuous endurance running on a treadmill of up to twice that of their wild-type littermates. Fortunately we have not yet reached the stage where human engineering of muscle is practicable or ethical. Breaking records – Have we reached the limits? The sprinter Usain Bolt holds the world 100 m world record at 9.58 s. Since Jim Hines broke the 10 s barrier in 1968, the world record time has only improved by a meager 3.7% despite expanding knowledge in weight training, fitness, nutrition and technological advances in tracks and footwear. We still do not have a clear explanation of why the best sprinters mainly come from the West Indies. Beating the system Chemical substances to enhance physique and physiological performance are now likely to be detected even in trace amounts in urine and blood samples including abnormal levels of hormones secreted naturally in the body, such as erythropoietin. Athletes need to think twice before taking anabolic steroids, painkillers, cold-relief tablets, or even drinking too much coffee. When records are broken, there is always a cloud of suspicion that performance enhancing drugs may have played a part. Many athletes still try and beat the system. It is acceptable to improve your hematocrit by training in oxygen depleted sites such as Mexico City (provided the industrial pollution does not affect you). It is not acceptable to have blood taken, stored and returned to the body just before a sporting event (autologous transfusion). There are now new tests to determine autologous transfusion or use of human growth hormone. These tests range from mass spectroscopy to proteomics. However, unethical athletes continually manage to be one step ahead of the scientific detection for doping. The latest fad includes exposure to xenon or argon gases, which are apparently able to increase production of erythrocytes, possibly by increasing internal production of hypoxia inducible factor 1 (HIF-1) leading to enhanced secretion of erythropoietin (EPO). The world anti-doping agencies are
Editorial / Acta Histochemica 117 (2015) 1–3
banning use of xenon and argon by athletes, but there is still no valid test to detect use of these noble gases. Exercise can damage your health Chronic exercise can result in major physical changes to the body. In the general population, an enlarged heart is commonly a sign of a serious physiological or pathological problem. However, athletes as a result of their intensive training regimes frequently develop cardiac hypertrophy, which is anything but normal. If you examine an athlete’s heart test, you know right away that it is abnormal. They have enlarged hearts that have increased in volume to adapt to their training method. Many Tour de France riders have developed hearts 40% bigger than normal – for strength, stamina, and endurance. Epidemiological data reveal that top class athletes, at the peak of human fitness, do not have a lifespan that differs from the non-active population. On the contrary, sports induced injuries (e.g. joint cartilage in runners, or brain injuries in boxers) are likely to impair general physical well-being when the sport is no longer practiced. Moreover, there is considerable circumstantial evidence that regular or intensive exercise can damage health. Since the early 1970s it has been recorded that chronic exercise is linked to impaired immunity. Not only does exercise not help ward off disease, but it would appear that the opposite is in fact the case. During most bouts of strenuous exercise, the number of neutrophils increases dramatically resulting in a major increase in white blood cell count (similar to that occurring during acute phases of an inflammatory response). This has been explained in part by the increased stress imposed by chronic exercise or competitive events having a deleterious effect on the thymus gland. There is increasing evidence that strenuous exercise increases endogenous release of stress hormones such as the glucocorticoids and also epinephrine (adrenaline). At the end of bouts of exercise the cortisol and epinephrine levels in the blood can be up to 15 times that of normal. Chronic or excessive exercise can have long-term deleterious health consequences. Runners enormously increase their chances of developing irreversible joint cartilage damage. Ask any longdistance runner why they devote so much time, energy and suffering to running, and the reply is usually that they cannot do without it. The satisfaction of challenge and the flush of endorphins accompanying exhausting exercise are compulsive and if they are ill or injured and unable to jog or run, they may fall into deep depression. It is probably anthropomorphic to declare that laboratory rodents appear to enjoy exercise, however this can be surmised. Caged rats and mice with free access to an exercise wheel willingly jog for extended periods without any additional encouragement. Researchers using rodents know that successful experimental exercise endurance studies, such as treadmill running, require gradual acclimatization and a progressive period of training before the
3
studies can be undertaken. This is also true for humans, without adequate training programs and acclimatization before extensive physical exertion, there is increased chance of physical damage to various systems, which can even be fatal. Most athletes reach their peak achievements before the age of 25 after which they lose their competitive edge owing to aging processes. With normal human aging there is a steady decline in strength and muscle weakness with loss of up to 40% of muscle mass (“sarcopenia”) in the elderly though regular mild exercise and good diet can help defer this muscle decline. Selection for sporting success Several large countries, including the former Soviet Bloc countries and China, aim for the pinnacle of the medals table at the Olympic Games and have established specialized sport academies with very early selection of potential sports talent. They are cultivating personalized genomics even involving preschool children, who are given intensive training over many years. In the West, it is more usual for scouts to discover talent at a much later age. Sometimes this can be at the expense of a normal education and lifestyle (e.g. the College Basketball system in the USA seeks abnormally tall and talented teenagers). Accepting the fact that successful competitive athletes are physical freaks means that countries with the largest population of freaks to select from will continue to dominate the Olympic winners’ podium. Why should a dream team of giants dominate basketball games just because they are freakishly tall? We could of course try to level the playing field by adopting some rules of horseracing and introduce handicaps in athletics and games to help reduce the odds. This is unlikely to happen as long as we remain fascinated by the abnormal such as the modern Goliaths and Titans, the circus strongmen or acrobats. Why else does the Guinness Book of Records remain a perennial bestseller or why do couch potatoes in such large numbers continue to be glued to television broadcasts of the greatest sporting freak shows on the planet. Fortunately extensive TV coverage (now in widescreen HD) of the major sporting events allows voyeurs and couch potatoes to experience in closeup the trials and tribulations of our modern day warriors and freaks in the arena. Raymond Coleman Acta histochemica, Department of Anatomy and Cell Biology, Rappaport Faculty of Medicine, Technion – Israel Institute of Technology, PO Box 9649, Haifa 31096, Israel E-mail address: [email protected] 16 October 2014