This past week, the world record for oldest person to run a full-length marathon was broken by Fauja Singh, a 100 year-old man who currently lives in England. His finishing time of 8:16:25 is almost exactly four times longer than the current men's marathon world record (2:03:38 by Patrick Makau, of Kenya), which is none too shabby for a centenarian. But the achievement is as instructive as it is remarkable, for Mr. Singh's example reinforces current theories on the subject of overtraining in endurance athletics.
An understanding of overtraining, while fragmentary, has only begun to take hold in competitive distance-running circles over the last few decades. As Dr. Tim Noakes notes in his work The Lore of Running:
"When I was running competitively in the 1970s, the concept that runners could train too hard was anathema and was quickly dismissed by runners with whom I ran. Indeed, an early article I wrote on the topic was passed off as evidence that I was just too lazy."
Yet according to Noakes, "the signs were everywhere. Dave Bedford, the hardest trainer of the era, performed poorly in the 1972 Olympic Games. My friend Dave Levick, who won the 1971 London-to-Brighton Marathon and the 1973 Comrades Marathon in record time after finishing second in the 1971 race, performed increasingly poorly the harder he trained in later years. The performances of Alberto Salazar, who trained and raced hard in the late 1970s and early 1980s, suddenly fell off precipitously" (Noakes, The Lore of Running, 4th Edition, 510).
But what is overtraining? The word itself suggests it involves training too much, but that doesn't tell us a lot. How does training too much affect the body?
Muscle damage appears to be one element. Several studies in the 1980s found that marathon running led to muscle damage requiring upwards of six-weeks from which to recover. It was noted in one of these studies that "veteran runners did have some areas of fibrosis in their muscles, suggesting incomplete repair." That study suggested that the muscles damaged most were those most energy depleted. However, Dr. Noakes suggests that "it is the persistent and repetitive eccentric loading of the muscles, and not energy depletion, that causes this muscle damage" (Noakes, 501).
Evidence also suggests that the fatigue associated with overtraining may be due not only to damaged muscles, but also a reduced capacity of the brain to recruit muscles during exercise. Dr. Noakes suggests this could "act as a protective mechanism. By preventing the athlete from continuing to train when in the overtrained state, the brain is acting to prevent any further damage" (Noakes, 505).
Finally, some studies suggest that overtraining reduces the ability of the body to respond to stress due to exhaustion of the hypothalamus, which regulates the body's hormonal response. Exhaustion of the hypothalamus has been noted in athletes who trained heavily (125-200km a week), though the degree of exhaustion was less than that of overtrained athletes.
To all this, Dr. Noakes states:
"To summarize, bodily changes caused by overtraining include the following:
-Histological changes in muscle, including evidence of muscle fiber and mitochondrial abnormalities. In athletes who suffer from impaired athletic performance after years of decades of heavy training, there may also be alterations in the genetic material in the exercised muscles, suggestion that those muscles have a reduced capacity to respond to the stress of exercise, to repair damage after exercise and to adapt to training.
-A reduced capacity of the brain to recruit the muscles used in the activity for which the athlete is trained.
-A reduced capacity of the hypothalamus-pituitary-axis to mount the normal hormonal response required to adapt to any external stress, including daily heavy training.
-Reduced sympathetic nervous system activity both at rest and during exercise (Foster and Lehmann 1997, Lehmann et al. 1997" (Noakes, 507).
In his concluding remarks on overtraining, Dr. Noakes states that, "...the evidence is absolutely clear. The body only has a finite capacity to adapt to the demands of intensive training and competition. Runners must choose, early in their careers, whether to spread that capacity over a long career, as did Bruce Fordyce and Ironman triathlete Mark Allen, or to use it up in a spectacular but short career, as did Buddy Edelen, Ron Hill, Alberto Salazar, and Steve Jones. This is the reality that both elite and nonelite athletes must confront every day that they run" (Noakes, 513).
I've quoted from Noakes extensively so as to provide a fairly clear conception of how scientists understand overtraining today. Given these conclusions, one might then be tempted to question how a 100 year-old could run a marathon. Examining the facts behind this effort offers some clues.
Perhaps most importantly, Fauja Singh was not a life-time competitive athlete, or for that matter a runner at all. As the article linked at the beginning of this post states, Mr. Singh did not begin running until he was 89 years-old. This point supports Bruce Fordyce's conclusions about master marathon records. He states that:
"The Masters [marathon] record can and will be broken, but it will be broken by a young master, a fresh master (my emphasis). By that we now understand to mean a 50 year-old who only started running in his [or her] forties. This would be a runner who has not grown ring weary and whose legs were still relatively fresh for the task of running 42km in close to 2:30. The runner will break the record, but will probably rue the fact that he didn't discover his talent in his twenties."
Mind you, Fauja Singh is twice the age of the masters runner described by Bruce Fordyce. But the record about which we're discussing isn't one of speed, but rather of longevity. And on this point, Fordyce's prediction is dead on. Mr. Singh didn't start running until he was 89 years-old, suggesting that his legs had not developed the long-term muscle damage associated with years of heavy training. Given this, it seems unlikely that similar feats will be accomplished by elites like Ryan Hall, Haile Gebrselassie, or current world-record holder Patrick Makau. The training that allows them to run world-class marathons in their youth could wear them out by the time they reach middle age.
So what can we take from all this? First, that the human body, while extraordinary in many ways, is also fragile. Franz Stampfl, Roger Bannister's coach when he broke the 4-minute mile, was caught on a torpedoed ship during World War II. From his experience surviving 8 hours in frigid North Atlantic waters, he concluded that the body was stronger than many thought. His conclusion is not unwarranted, and time and again we have seen the amazing capacity of the human body to adapt to training; the Japanese "marathon monks" are one remarkable example. Yet based upon the evidence elucidated above, this capacity appears to come at a cost. As Noakes states in his discussion on treating overtraining:
"That some athletes run long distances, including marathons, with distinction does not prove that the human body is a marathon machine any more than the conquest of Everest indicates that humans are a high-altitude species. Both indicate the extreme adaptive flexibility we have inherited. While we adapt well to a variety of opposing stresses, humans are generalists, and we lack the ability to adapt specifically to any single, severe stress, such as competitive distance running, for any great length of time" (Noakes, 509).
This point may become evident in the coming years. As we discussed in our Memorial to Sammy Wanjiru, one big trend in contemporary distance running is the tendency of talented 5k and 10k runners to take on the marathon in the prime of their career, largely because monetary incentives. This tendency has led to an marked increase in the frequency of fast marathons in recent years, especially (for the men) those falling under 2:05. Yet with so many younger marathoners taking on the intense schedule required to train for and race marathons, it seems likely that the incidence of overtraining will increase among these athletes in the coming years. The fact is that the incentives in competitive distance running make it attractive to train exceedingly hard in a short window, even if such training leads to serious health concerns in the future. The lure of a gold medal, a world record, or serious prize money, could lead to spectacularly brilliant and short running careers for today's crop of talented distance runners the world over.
A similar problem may already be happening in the United States, where most young competitive runners compete on their high school or college teams. One potential problem with this set-up is that the finite number of seasons available to high school and collegiate runners gives them (and their coaches) compelling incentives to train very hard to achieve short-term results. In my experience, winning the conference before graduation is a big incentive for many to pile on the miles during off-season training, or to put oneself through punishing workouts several times a week. Yet these practices appear to be the primary causes of overtraining, which can lead to premature decline in running ability. Talented athletes who are subjected to this type of training time and again come up short in the big competitions. The damage done prevented them from allowing their superior talent to shine.
So what can be done? Chiefly, it seems imperative to avoid overtraining. Both Tim Noakes and Jack Daniels, an exercise physiologist, emphasize the need to "achieve as much as possible on a minimum of training." The improvements on performance due to training are considerable, but not unlimited. As Daniels suggests, a cross-country coach at a college or high school should aim to improve his or her runners' times approximately 10% from their freshman year to their senior year. Further improvement might be possible, but 10% is about what one can reasonably shoot for under most circumstances.
Noakes appears to agree in principle, highlighting the genetic component of performance. As he points out, "who ever records that exceptional runners like Walter George and Alf Shrubb achieved quite remarkable performances on very low mileage? George ran a mile in 4:10.6 and a 16km run in 49:29 on little more than 3km of training per day. Even Paavo Nurmi, the most medalled Olympic runner of all times, trained pathetically little but performed exceptionally, even by today's standards" (Noakes, 291-292) Furthermore, Bill Bowerman, a former coach at the University of Oregon, usually kept his runners at or below 120km a week. The system he pioneered produced decades of collegiate dominance.
Therefore, it's important to bear in mind that while training is essential for elite athletes, it is not everything. In order to maximize one's potential, it appears imperative to work hard, but not so hard as to overtrain. Exceeding effort, ambition, and drive appear essential to success in most fields. Yet within these virtues of elite performance also reside the seeds of potential, premature decline. The need to understand how the training leads to the desired result, in this light, appears essential. As Arthur Lydiard, a famous running coach from New Zealand, once said to an assembly in Osaka, Japan:
"' Suppose you look back at the last season and there is one day where everything went right and you ran your best time of the year. If you know why you ran so well that day and you put your training together so as to produce your top form the day of the Olympics or the Japanese Championship or whatever big race you are pointing for, then you know something about training, but until you can do that, you don't know anything about training. You are just a good athlete who one day might run a good race, but you don't know when, so there's a need for better evaluation and understanding of each aspect of training, as well as how to put them together in a balanced way" (Link).
I encourage you consider the evidence and ideas presented here not as concrete fact, but as insights made by those who have studied the human body and athletic performance in a thorough way. New evidence may yet emerge which overturns these conclusions, but in light of the scientific evidence regarding distance training, it seems important not to overdo it, be it in running or any activity in life. That of course depends on how you you think about things. A famous survey once asked people what they would do if given a pill that would make them an Olympic champion, but kill them a year later. 50% said they would take the pill. Given those results, it seems fair to say that advice regarding overtraining will be taken in a variety of ways. Regardless, however, the above discussion may prove useful.
Happy Thursday, friends :).
No comments:
Post a Comment