LONGEVITY and CAUSES of DEATH of ATHLETES Keiji

J. Human Ergol., 6: 15-27, 1977

LONGEVITY AND CAUSES OF DEATH OF ATHLETES

Keiji YAMAJIand Roy J. SHEPHARD

Department of Physical Education, Faculty of Education, Toyama University, Toyama, Japan Department of Preventive Medicine and Biostatistics, Faculty of Medicine, University of Toronto, Toronto, Canada

Since Morgan, many research workers have attempted to answer the question whether intensive training and athletic competition can alter life span. A review of the literature yields few clear conclusions. The difficulty seems that the human life span is affected by a multiplicity of factors including physical characteristics (sex, age and body type), life- style (factors such as habitual activity, smoking and drinking habits and diet), environmental variables (air and water quality, exposure to sunlight, noise etc.), physiological factors, personality and inheritance. Relative to these confounding factors, athletic competition usually occupies too short a portion of the life span to have a significant effect on longevity. The important question may well be not the kind of sport pursued or the intensity of the required training, but whether the activity is continued to an advanced age.

The average length of human life has increased greatly since Roman times (a gain of 20-30 years) (KARPOVICH,1941). In the United States, life expectancy averaged 46.3 years for males and 48.3 years for females in 1910, but these figures increased to 58.1 and 61.6 years in 1930, 65.6 and 71.1 years in 1950, and 67.1 and 74.6 years in 1970, respectively. By 1974, the average US male lived more than 68 years, and the average US female more than 76 years (The World Almanac, 1976). The expectation of life now exceeds 70 for males and 75 for females in Denmark, Iceland, Norway, Sweden and Japan. Nevertheless, the trend to a longer average length of human life is continuing. Among possible reasons for this remarkable increase of average longevity are progress in medical care (control of major infectious diseases, new medical and surgical techniques and appliances, better hospital facilities and more universal availability of health care), improved programmes of public health and social engineering, better motivation, a higher general standard of living, and a more general knowledge of the principles of hygiene and child care. In partic-

Received for publication March 14, 1977

15 16 K. YAMAJI and R. J. SHEPHARD ular, medical progress has brought about a decrease in the mortality rate for babies and infants (perinatal and infant mortality) (Demographic Yearbook, 1973). In contrast, there have been reports of sudden death among trained athletes performing various sports (JAMESet al., 1967; JOKLand MELZER,1940; JOKLand McCLELLAN,1970; KARPOVICH,1941; OPIE, 1975; SHEPHARD,1974; WILENS,1964; WOLFand BING, 1965) and there are indications that the number of such incidents is increasing. In relating longevity to physical fitness, we must consider dimensions of "time and space ." Time may be either the total life span or the period over which we can live a healthy life; space is the physical working capacity or the amount of work that can be accomplished within the limiting time. The two dimensions are sometimes in opposition to each other. Thus, in many sports events, the working capacity is used competitively, and in order to achieve ex- cellence the sportsman may choose to disregard the question of how long he can live a healthy life. Nevertheless, most exponents of physical activity have cherished the hope of improving the quality and quantity of life, and it seems likely that vigorous activity will continue to be suggested for this purpose in the absence of some drug producing comparable beneficial effects on the cardio-respiratory system. A substantial number of investigations have recognized that moderate physical exercise improves cardiorespiratory function, working capacity and mechanical efficiency in both the general sedentary population and in patients with certain specific disease conditions. In addition, there have been reports of psychological benefits, including an improved self-image and a feeling of greater well-being (MITCHELLand BLOMQVIST,1968; POST, 1970; POWELL,1975). Unfortunately, existing studies give little insight into the mechanisms underlying such improve- ments, and fail to define an intensity, duration and frequency of physical exercise that is effective in producing gains of working capacity yet avoids harmful side- effects on physical health. The present report reviews existing data on exercise, longevity and causes of death.

LONGEVITY OF ATHLETES

Comparison of sportsmen and control subjects. The question whether vigorous training and participation in strenuous athletic events can cause serious physical damage or premature death has been debated since the early history of medicine. Hippocrates believed that intense athletic competition had a harmful effect on the heart and other body organs, lowering resistance to disease (HARTLEYand LLEWELLYN,1939). Until the work of Morgan, published in 1873, the viewpoint prevailing in England was that competitive oarsmen did not live beyond 50 years of age, their limited longevity being caused directly by participation in athletic LONGEVITY AND CAUSES OF DEATH 17

competition (MONTOYEet al., 1956). MORGAN(1873) carried out a follow-up investigation on 294 oarsmen who had participated in Oxford versus Cambridge boatraces between 1829 and 1869. His results showed that these oarsmen lived about two years longer than the "average Englishmen" of insurance statisti cs. MEYLAN(1904) similarly studied the after-histories of 123 men who had rowed in the Harvard University crews from 1852 to 1892. The life expectancy of the Harvard oarsmen was 2.88 years longer than predicted from mortality tables; furthermore, there was no evidence that the Harvard oasmen were particularly vulnerable to death from heart disease. These results were confirmed by many subsequent reports, all of which compared data on college or high school athletes with either insurance tables or the life- expectancy of the general population (ANDERSON,1916; DRINKWATERand SAN- DERS, 1929; GREENWAYand HIscocK, 1926; HARTLEYand LLEWELLYN,1939; KNOLL,1938). HARTLEYand LLEWELLYN(1939) noted two important criticisms of these early investigations : data were compared with average insured males, and no attempt was made to distinguish that percentage of deaths due to accidents and suicides. DUBLIN(1928, 1932), RooK (1954) and PROUT(1972) all pointed out that the life expectancy of both honour and average graduates of this period was substantially greater than that of the general population. GREENWAYand HIscocK (1926), and WAKEFIELD(1944) also indicated that the mortality rate attributable to accidents and suicides was greater for former athletes than for non-athletes. While DUBLIN'S(1928) studies confirmed that the mortality rate of crewmen was lower than anticipated, when the athletes were divided on the basis of age, the mortality rate for crewmen under the age of 45 years was 20 to 40 per cent greater than that of the average insured man. Results of ROOK(1954) also showed that the average age of death for sportsmen (67.97 yrs) was nearly a half year later than that for a control group (67.43 yrs) made up of men who had studied at the same university. However, the average age of death for the crewmen (67.08 yrs) was lower than in other reports and lower than for a random sample of the university population. Furthermore, the higher mortality rate of the crew members was due mainly to a high mortality rate (15.9 %) under 50 years of age, figures for this period being 15.9% in the rowers, and 13.3% in the randomly selected group. Thus results of both DUBLIN(1928) and ROOK(1954) supported LEHMANN(1897) . MOORSTEIN(1968) reported that several well-known British and American oarsmenn had died relatively early, the cause of death being such conditions as a rupturedd appendix, tuberculosis or an overwhelming infection. ROUT(1972) attempted to explain the shorter life span of crewmen in terms of the requirements of crew races, particularly the need to control breathing, withh associated very slow resting pulse rates (normal sinus rhythms in the 50s and even the 40s). The ECGs of some oarsmen showed coronary nodal rhythms and 18 K. YAMAJI and R. J. SHEPHARD sinus bradycardias. Such unusual features of the electrocardiogram may reflect the high aerobic demands of rowing (200-250 kcal expended over 7 to 20 minutes) (DIPRAMPEROet al., 1971; HAOERMANand LEE, 1971; ISHIKO,1967b; JACKSON and SECHER,1976; NOWACKet al., 1969). These work loads may be sustained in the face of quite low values for relative maximal oxygen intake and heart volume, although oarsmen have large absolute maximal oxygen intakes and heart volumes compared to swimmers and distance runners (MEDVEDand MEDVED,1976). In summary, these early studies (1873-1956) found that physically demanding programmes of competition had no significant effect on longevity. In 1968, a letter to the Journal of the American Medical Association stating that all the members of 1948 Harvard crew were already dead was denied by every one of the individuals concerned (MoORSTEIN,1968). However, the discussion on the longevity of athletes was re-opened. ISHIKO(1967a) reported that the survival rate of former athletes from Tokyo University was longer than that of either average Japanese subjects or medical doctors who graduated from the same university during the same period. Japa- nese university athletes tended to live longer than other graduate students, in dis- agreement with the reports of DUBLIN(1928), RooK (1954), POLEDNAK(1972a) and PROUT(1972). SCHNOHR(1971) compared the mortality of 297 male athletic champions born in Denmark between 1880 and 1910 with that of the general Danish male population. The unique point of his study was that his subjects were champion athletes, rather than university athletes. The mortality between 25 and 50 years of age was 39% less for the athletic champions than for the general male population (p<0.05). However, the mortality rates from 50 to 64 years and 65 to 80 years were the same as in the general population. A somewhat similar study by KARVONENet al. (1974) is more widely known. He picked 396 Finnish champion skiers who were born between 1845 and 1910, following this population to the end of 1967. The Finnish champion skiers had a life expectancy three to four years longer than that of the general male population of Finland. However, it remains difficult to determine whether the lower mortality of the Finnish champion skiers was a cause or an effect of their previous sports career. PROUT(1972) examined data for 172 graduates of Harvard and Yale, each of whom had rowed in the four mile inter-varsity race at least once from 1882 to 1902. The average life spans of the 90 Harvard and 82 Yale crews were 67.79 and 67.91 years respectively. These averages were 6.24 and 6.35 years longer than data for randomly selected classmates (significance of combined Harvard and Yale data, p<0.01). Comparison of different sports. It is likely that the intensity, duration and frequency of physical activity differ among the various sports. If training and competition affect the average life span of athletes, the effect should then differ LONGEVITY AND CAUSES OF DEATH 19

between sports. DUBLIN(1928) compared the average life span of 4976 university athletes who graduated prior to 1905; the group had engaged in various sports including: football (N=1233), track (N=1076), crew (N=576), baseball (N=1111) and two or more sports (N= 822). The mortality was lower than expected in every sports group (baseball, 98.0%; crew, 94.1 %; track, 91.8 %; football, 88.3%; two or more sports, 78.3 %). The lowest mortality rate was found in the group who engaged in two or more sports. Dublin classified the athletes into two age groups (under and over 45 years old). The mortality rate for the rowers under 45 years of age was 20 to 40 per cent above that of the average "American insured male" and 40 to 65 per cent above the mortality figure calculated for other classes of athlete. ROOK (1954) also compared mortality rates among sports, excluding deaths due to war and accidents. The lowest average ages of death were for rowers (67.08 yrs) and rugby footballers (68.84 yrs). The high mortality rate of the rowers was due in part to a high mortality rate (15.9%) under the age of 50 years, comparable data for other sports groups being for track and field athletes 13.4%, crick- eters 12.7%, and rugby footballers 10.5 %. His results supported DUBLIN'S(1928) contention, but disagreed with the reports of MORGAN(1873), MEYLAN(1904) and HARTLEYand LLEWELLYN(1939) that oarsmen did not die young. In 1972, LARGEY(1972) and POLEDNAK(1972a) further examined generaliza- tions by SCHNOR(1971) in relation to specific sports (Table 1). LARGEY(1972) showed the somewhat surprising statistic that American football players lived an average of only 57.4 years, a significantly shorter period than baseball and track athletes (p<0.01). Furthermore, the short life span of the football players was due to the low percentage who lived past the age of 50 years. POLEUNAK(1972a) reported that the shortest life span was 65.2 years for baseball players and the long-

Table 1. Mean life-span of various sportsmen, excluding athletes who had died at war or by accident.

N, number of cases; SD, standard deviation. 20 K. YAMAJI and R. J. SHEPHARD est life span was 67.2 years for men gaining "letters" in two or more sports. Differences among these five groups, all <2.0 years, were not statistically significant. Among the groups of sports reviewed, we may conclude that track and field and participation in two or more sports confer a slight advantage, while American football and baseball players have a slight to substantial disadvantage of longevity. Nevertheless, discrepancies of mortality rates among the different sport groups are small and commonly within the limits of statistical error. One possible explanation of any real differences may be found in the charac- teristic physiques of the various classes of athletes. The relationship between physique and longevity. Overweight in proportion to height is associated with various diseases, including ischaemic heart disease, diabetes, cerebrovascular disease, renal and hepatic disease. Life insurance companies have regarded physique as an important determinant of longevity. Sportsmen tend to put on weight when they participate in certain forms of sport at university (MONTOYE,1967; POLEDNAKand DAMON,1970; ROOK, 1954). The weight gain of athletes after graduation also tends to be greater than that of controls (MONTOYEet al., 1956). Further, since it is likely that lean tissue is being lost after graduation, such weight gain may under-estimate the increase of body fat; it is well known that LB114as estimated from 40KKcounting gradually decreases with age after maturity, while body fat content progressively rises (BURMEISTER and BINGERT.1967; FOREESand REINA,1970; MYHREand K.ESSLER,1966). MONTOVE(1967) reported no clear inter-sport differences of body weight changes, although the track men and baseball players appeared to gain most weight and the football players least. CARTER(1970) analyzed morphological characteristics in 35 samples of champion male and female athletes (N=1039) from 14 different sports played at various levels of competition. He concluded that in terms of somatotype, the distance runners were characterized by ecto-mesomorphy andd meso-ectomorphy, American football players and baseball players were endo-mesomorphs, basketball players were low ecto-mesomorphs and rowers were mesomorphs. Early reports suggested that ectomorphic marathoners were particularly susceptible to lung disease, but at the present day, many of the lung diseases associated with an ectomorphic body build are curable, either medically or surgi- cally. Studies on the general population indicate that endomorphs have a shorter life span in our present culture (BIORCK,1972;DAMON et al., 1969; SHEEHAN,1973; SPAINet al., 1963). RooK (1954) studied the relationship between longevity and the body size of athletes. He divided the athletes (track and field), rowers and rugby players into heavy-weight (N=251) and light-weight (N=315) groups. The average age of death for the heavy-weight group (66.73 yrs) was 1.73 years earlier than that of the light-weight group, and was 0.7 years earlier than that of the randomly selected control group. ROOK (1954) next divided track and field athletes into 61 short-distance run- LONGEVITY AND CAUSES OF DEATH 21

ners (100 yards and 440 yards), 89 long-distance runners (1-3 miles and steeple- chase) and 53 men who took part in hammer and weight throwing contests . After excluding those who were killed in the war or had died from accidents, the average percentage of short-distance (57%) and long-distance runners (56%) who lived to over 70 years of age was higher than that of the hammer and weight throwing men (34 %). However, the numbers involved were small, and differences were not statistically significant. PoLEDNAKand DAMON(1970) compared the physique of former major athletes, minor athletes and non-athletes. The athletes were found to be fatter , more muscular, and stockier than the non-athletes, and major athletes tended to be more so than minor athletes. The stocky, muscular person, the endomorphic mesomorph, has been shown to have a shorter life span than the lean person of insurance records (Society of Actuaries, 1959). The authors concluded that since former major athletes had an endomesomorphic physique, this factor, independent of any effect of sports participation, could account for their shorter life span . Since endomorphy and high mesomorphy are more frequent in athletes than in non-athletes, and sportsmen tend to gain weight after giving up strenuous training, former athletes have significant risk factors for cardiovascular disease. Former athletes should continue to exercise until they reach an advanced age, if they do not wish to gain weight with a resultant shortening of their life span. Degree of participation and achievement. POLEDNAKand DAMON (1970) studied men born between 1860 and 1889 who had spent two or more years at Harvard University. The population was classified into three groups, i.e., (1) majorr athletes : N=177 (baseball, football, crew, track, ice-hockey and tennis) (2) minor athletes : N=275 (basketball, cricket, fencing, golf, lacrosse, polo, swimming and wrestling) (3) non-athletes : N=1638. After searching records to determine the percentages of men reaching the ages of 70 and 75, the highest proportion of survivors was found among minor athletes, the difference from the other two groups being almost significant. The difference between major athletes and non-athletes was not significant, although non-athletes were inclined to live longer than major athletes. PoLEDNAK(1972a) studied the same question, but used a larger number of subjects and analyzed his results in more detail. He also concluded that minor athletes had a greater longevity than the other two groups. Subjects were classified according to the total number of athletic awards (letters) won. The average age at death was later for one-letter athletes (67.1 yrs) than for two letter athletes (66.4 yrs); differences among the three groups were statistically significant. His reports suggested that minor athletes who participated in moderately active sports lived longer than major-athletes and non-athletes, and as the number of letters increased, the mortality rate increased. The weakness of this study was that many of the men listed were still alive. We might expect that the Danish champion skiers (SCHNOHR,1971) and 22 K. YAMAJI and R, J. SHEPHARD

Finnish champion athletes (KARVONENet al.,1974) had trained at close to maximal effort for a long time. As previously stated, the average mortality rate for such champions was less than that of the general male population, at least under 50 years of age. SCHNOHR(1971) concluded that since the leading cause of death in this age-group was cardiovascular disease, the better survival of the former athletes was probably produced by cardiovascular training. Relationship between later habits of ex-athletes and longevity. In a cross- sectional study, MONTOYE(1967) compared ex-athletes with non-athletes and found that a slightly higher percentage of the former engaged in drinking and smoking. Differences of these habits between sport specialities were insignificant. In contrast with this American data, KARVONENet al. (1974) indicated that the percentage of smokers among former endurance skiers was less than in non-athletes. This discrepancy probably reflects a difference between endurance and other classes of sportsman. As many investigators have agreed, smoking is a prime factor in the causation of cardiovascular disease, malignant tumours, and other causes of early death. M0NTOYE's(1967) former athletes were thus at greater risk of such diseases than the general population as age advanced. In addition, we cannot neglect the influence of inheritance upon the likelihood of cardiovascular disease and malignant tumours (MONTOYE,1967; PAFFEN- BARGERand WING, 1967; SCHMID,1975). Longevity of females. The relationship between physical exertion and longevity in female athletes has not been considered previously. However, many sports physicians have stated on remarkably slender evidence that vigourous training and competition in sports and games can have a harmful effect on pregnancy, childbirth and problems of the immediate post-partum period. ZAHARIEVA(1972) collected statistics on pregnancy and childbirth among women who had participated in the Olympic games. Olympic participants generally had a normal pregnancy. After childbirth, the physical performance of the competitor was better than before; they felt physically more stable and better balanced emotionally. Other more recent reports (ERDELYI,1962) confirm that athletic competition has no harmful effect on pregnancy, childbirth or the post-partum period.

CAUSES OF DEATH OF ATHLETES

While moderate training improves the function of the cardiovascular system, vigourous competition and severe training could lead to acute cardiovascular malfunction. We must thus discuss the likelihood of death from cardiovascular disease in former athletes relative to that of non-athletes. GLENDYet al. (1937) reported that former athletes who had participated ex- tensively in their sport had an increased risk of becoming coronary patients. On the other hand, GREENWAYand HIscocK (1926) found that the percentage of deaths LONGEVITY AND CAUSES OF DEATH 23 from heart disease was lower among Yale athletes than in their control subjects from the general population. ROOK (1954) found no evidence that cardiovascular deaths occurred at an earlier age in sportsmen. On the other hand, DUBLIN(1928) reported that athletes over the age of 45 showed a 12 % excess of deaths from heart disease. In contrast, PAFFENBARGERand WING (1967) examined the relationship between participation in university sports and fatal strokes, and concluded that 16 % of controls but only 7 % of stroke victims had participated in athletics at university. MONTOYE(1967) collected four studies of the causes of death among former athletes. He concluded that numbers of subjects were too small to allow con- fident comparisons, but that there was no indication of an unusually high incidence of cardiovascular deaths among former athletes.

Using MONTOYE's (1967) table as a model, we have added the results of several subsequent studies (Table 2). The percentages of heart and vascular disease in former athletes was higher than non-athletes in the data of ROOK (1954), POMEROY and WHITE (1958) and SCHNOR (1971), although individual differences were all within the bounds of statistical error. As several investigators have already indicated (DUBLIN, 1928; GREENWAY and HISCOCK, 1926), the percentages of suicide were higher in former athletes than in non-athletes. However, there were no remarkable differences between former athletes and non-athletes in the studies of POMEROY and WHITE (1958), ROoK (1954), SCHNOR (1971) and WAKEFIELD

(1944). WAKEFIELD (1944) found that the percentage of deaths from cardiovascular disease before or during World War ‡U was lower, both among athletes and controls than in more recent studies. While various reasons have been advanced for the "epidemic" of cardiovascular disease, one factor may be a decrease in the habitual activity of both populations. ROOK(1954) attempted to determine the differences in causes of death among various sports groups (athletics, 110 deaths; cricket, 99; rowing, 130; rugby, 100). Among rowers 31.5 % of deaths were due to cardiovascular conditions. This was low, as compared to 36.4-42.0% for other sports groups. However, 18.4% of deaths among the rowers were due to neoplasms, a significantly high figure compared with the rate of 10.1-13.6 % for other sports groups (p<0.05). There is little evidence why this should be the case. POLEDNAKand DAMON(1970) and POLEDNAK(1972a) attempted to determine the effect of exercise intensity by classifying athletes into three groups (major athletes, minor athletes and non-athletes). POLEDNAK(1972b) found that the percentage of deaths due to coronary heart disease in major athletes was significantly higher than that in minor athletes and non-athletes. He suggested that these discrepancies could be explained by differences of physique between the various classes of sportsman. POLEDNAK(1972a) further analyzed the mortality rate due to coronary heart disease, and recognized that three or more-letter athletes had the earliest mor- 24 K. YAMAJI and R. J. SHEPHARD

Table 2. Causes of death

tallty. He suggested that this reflected differences of physique and possibly of personality between groups (DAMONet al., 1969). However, POLEDNAK(1972a) admitted that the numbers in his sample were too small to reach a conclusion regarding the cause of death and the degree of participation and achievement in the various sports groups. As MONTOYE's(1967) studies have shown, former athletes are more likely to consume cigarettes and alcohol, and have a more mesomorphic, masculine body type than nonathletes. It is well known that such habits and such a body build increase the risk of cardiovascular disease. Nevertheless, the results of Table 2 do not show any clear tendency. Possibly, the adverse factors discussed above are counterweighted by the effects of training undertaken earlier in life. We may thus conclude there is no relationship between the cause of death and physical activity at university. However, subsequent weight gain, lack of exercise and smoking habits (JENKINSet al., 1968, 1971) increase the risk of coronary heart disease and malignant tumours (SCHMID,1975). Former athletes, like non-athletes should continue to exercise in later life. LONGEVITY AND CAUSES OF DEATH 25

among former athletes.

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