Medicine & Science in Sports & Exercise:
A History of Medical Reports on the Boston Marathon: 112 Years and Still Running
THOMPSON, PAUL D.; VENERO, CARMELO V.
Henry Low Heart Center, Hartford Hospital, Hartford, CT
Address for correspondence: Paul D. Thompson, M.D., Division of Cardiology, Hartford Hospital, 80 Seymour St, Hartford, CT 06102; E-mail: email@example.com.
Submitted for publication April 2008.
Accepted for publication July 2008.
Introduction/Methods: We performed a systematic search for medical reports on the Boston Marathon, run annually since April 19, 1897 and studied medically since 1899.
Results: We identified 66 articles: 25 were related to cardiology; 10, exercise physiology; 8, metabolism; 5, neurology; 4, gastroenterology; 3, hematology; 3, several disciplines; and 8, nephrology, orthopedics, and general topics. The predominance of cardiology articles reflects concerns about the cardiac risks of exercise present in the early 20th century and persistent to this day. The authors and contributors included luminaries from the medical and exercise community including Drs. Paul Dudley White, Samuel Levine, Kenneth Cooper, Paul Zoll, Ellsworth Buskirk, and David Costill. The articles identified or confirmed many of the presently accepted principles of marathon medicine.
Conclusions: Medical studies on the Boston Marathon not only provide lessons applicable to managing modern athletes but also demonstrate the interests and concerns of researchers who have used the event to study the physiology of prolonged exercise for more than a century.
The first Boston Marathon on April 19, 1897 was organized by members of the Boston Athletic Association (BAA) inspired by the Olympic Games' revival and its marathon the year before (65). The race was run for the 112th time in April 2008, although a military relay replaced the individual race in 1918 during World War I (13). In only its third running, two Tufts professors examined urine and hematological changes associated with the event (71). Studies on Boston represent a large proportion of studies on marathon medicine probably because of the race's longevity, interest in the event among the Boston medical community, and a supportive research environment. This review examines the history of Boston Marathon medical studies and their contributions to our knowledge of endurance exercise.
We performed a systematic literature review for medical reports performed on the Boston marathon. We searched PubMed through December 2007 using "Boston Marathon" or "marathon" and identified additional articles from prior citations. We also searched the table of contents of the New England Journal of Medicine and its predecessor, the Boston Medical and Surgical Journal, from 1897 to 1970 to identify articles not included in PubMed. This search yielded one letter not previously identified (5). Boston was not specified as the marathon in six articles (27,37,51,57,62,67), which were included because Boston was the likely event.
OVERVIEW OF THE RESULTS
We identified 66 articles (Table 1) that identified or confirmed multiple physiologic principles (Table 2). Most articles addressed cardiac issues because there was widespread concern at the start of the 20th century that prolonged physical exertion produced adverse cardiac effects (65).
The authors of articles on Boston include luminaries from the medical and exercise physiology community. Dr. Samuel A. Levine (23,24,36) was the originator of "Levine sign" or the patient's use of a closed fist to describe the discomfort of angina pectoris (16) and an early advocate of decreasing bed rest for myocardial infarction patients (35). Dr. Paul Dudley White (69) was an internationally known cardiologist and an early exercise advocate. Dr. White diagnosed his own angina when he developed chest pain while jogging to view the finish of the 1967 Boston race (65). When Dr. White died, an obituary started with, "Practically everyone knows that Dr. Paul Dudley White rode a bicycle and preached exercise" (65), and the Boston Herald American published a cartoon of White bicycling in the clouds over Boston (Fig. 1). Dr. Ellsworth Buskirk (8) directed the Noll Human Performance Laboratory at the Pennsylvania State University and served on that faculty from 1963 to 1992. Dr. David Costill (10,11) became a well-known exercise physiologist at Ball State University. Dr. Kenneth Cooper (42,49) wrote the book Aerobics.
FIGURE 1-Cartoon of ...Image Tools
STUDIES 1899 TO 1930
Williams and Arnold authored the first report on Boston in 1899 (71). Only 17 ran the race; 14 finished and 13 participated in the studies. Each participant was accompanied by an "ambulance corps" member riding a bicycle. The only injury that occurred was when one of these bicyclists hit a dog (71).
Six finishers had oral temperatures ≤94°F, the lowest value of the thermometer. All six whose urine was examined had albumin after exercise, one of the earliest observations of "athletic pseudonephritis." Eleven of the 13 had "mitral regurgitation" murmurs after exertion. The papillary muscles were known to prevent regurgitation so the runners' murmurs were attributed to "exhaustive hearts" (71) and relaxation of the "mitral sphincter" (6). Blood pressure was not measured in early studies. Arterial tension was measured by a thistle tube connected to a tambour, which recorded pulse amplitude on a soot-covered, rotating drum (6). Low arterial tension was also attributed to cardiac fatigue (Fig. 2). To determine cardiac dimensions, tracing paper was placed on the chest and cardiac dullness delineated by percussion (71) (Fig. 3). Cardiac size was increased in most runners before the race, and 7 of 10 runners demonstrated further enlargement after the race, also attributed to cardiac fatigue (71).
Blake and Larrabee (6) used the 1900-1902 races to comprehensively examine marathon physiology but were assisted by others physicians not listed as primary authors. The findings were remarkably insightful for their time.
Increases in heart rate after the race were "often surprisingly small" and depended primarily on how hard the athletes ran "particularly in the last few minutes of the race" (6). Similar observations that lactate levels increased primarily with a finishing sprint would not be made for another 66 yr (11). The best-trained runners had the slowest prerace heart rates, a concept not widely known until 1940 when White reported bradycardia in four distance runners (65). This report (6) was among the first to note that oral temperature was "not a reliable factor" and that rectal temperatures usually increased after the race (6).
Prerace samples in 1901 were transported to Boston for examination, whereas the 1902 samples were examined in Ashland, and the researchers took a "later train" back to Boston (6). This detail highlights that Ashland was the initial Boston start because trains could transport competitors from the city (13). Ashland remained the starting point and the race was only 40 km long, until 1924 when Boston served as the American Olympic Marathon Trial and the course increased to the Olympic distance of 42 km or 26.2 miles (13). There was marked leukocytosis with white blood cell counts of 14,200-27,700 after the race (6). Most of the increases were caused by an increase in polymorphonuclear cells (PMN), but seven of nine subjects demonstrated myelocytes, a potentially clairvoyant observation given recent evidence that circulating stem cells increase after exercise (63). Leukocytosis was correctly attributed to PMN demargination or release of leukocytes from their "rest in the great internal veins" (6).
Urine contained albumin in only 4 of the 30 specimens before, but in all after, the race. Postrace samples also contained hyaline, granular, and epithelial cell casts and blood expanding the findings of athletic pseudonephritis.
Ten runners examined using the percussion/tracing technique showed symmetrical cardiac enlargement, an early recognition that endurance training enlarges all four cardiac chambers (64). There was further cardiac enlargement after exercise, attributed to cardiac decompensation and "cardiac fatigue." "Bleeding from the mouth or nose did not occur" (6), a reference to the absence of pulmonary edema and an indicator of the authors' concern about cardiac failure (6). This concept of cardiac fatigue would reappear 84 yr later with echocardiographic evidence of impaired cardiac function after triathlons (15). Because of concern about acute cardiac failure, Paul Dudley White obtained arterial pulse tracings on runners in the 1916 race (68) and was reassured by the absence of pulsus alternans, a sign of severe heart failure.
Gordon et al. (24) measured vital capacity (VC) and cardiac dimensions in the 1923 race. VC decreased 17% after the race. VC in the runners was similar to normative values, and there was no relationship between VC and performance, indicating that training did not increase VC and that performance was limited "by the legs rather than by the wind" (24). Radiographs were obtained immediately after the race using a portable machine placed in the BAA clubhouse 100 yards from the finish. Cardiac size was determined by cutting out the cardiac silhouette and weighing the resultant x-ray film (21). There was no cardiac dilatation after exercise, and postrace cardiac size was small, probably because of venous vasodilatation from the exercise and the upright posture required for the x-ray studies.
The first serological study was performed in 1924 (36). Blood glucose fell in most of the 11 runners (36), and their condition at the finish correlated with their blood glucose. Levine et al. (23,36) noted that those "with low blood sugar presented a picture of shock not unlike that produced by an overdose of insulin." This report appeared soon after Banting and Best's discovery of insulin in 1921. They speculated that the "state of shock…could either have been prevented or at least ameliorated if a larger supply of carbohydrate had been taken in the diet the night before or the morning of the race" (36). According to personal notes provided by Dr. Samuel Levine's son, Dr. Herbert Levine, Professor of Medicine at Tufts, these studies interested Dr. Elliott Joslin because they supported Joslin's belief that exercise could help overcome insulin deficiency. Much later studies would show that exercise decreases blood glucose by both insulin-dependent and -independent mechanisms (28).
STUDIES 1930 TO 1960
Only three reports appeared during this period possibly because the Great Depression and World War II diverted medical attention from the event (5,20,22). Gordon (22) reported that runners followed for 6 yr after the marathon did not develop cardiac problems. On the other hand, in a comment that would presage studies on the acute cardiovascular risks of exercise, he noted that among individuals of the "well-developed 'angina type" … athletic competition should be undertaken cautiously."
Behrman (5) observed an increase in albumin in 19 of 20 runners from before to after the 1941 race. Gilligan et al. (20), undoubtedly influenced by the war effort, studied "march hemoglobinuria" in the 1941 race. Plasma hemoglobin levels were increased after the race in 18 of 22 runners. Spectrophotometric studies confirmed that this was hemoglobin and not myoglobin. Red cell fragility studies on six runners, five with hemoglobinemia and one with hemoglobinuria, were normal. The concept of exercise hemolysis would be popularized years later by Dr. Randy Eichner. The authors (20) were assisted by Dr. Paul Zoll, subsequently a pioneer of cardiac pacing and defibrillation.
STUDIES 1960 TO 1970
There were only three studies published during this period (8,11,47). Buskirk and Beetham (8) measured body weight and rectal and skin temperatures in an unspecified Boston race, the Brighton 18-mile race, and a training run. Data from Boston are provided for seven marathoners, but for unspecified reasons, finishing times are provided for only four. Marathoners lost 6% of their body weight and increased their rectal temperatures by 1.9°C. The highest rectal temperature was 39.8°C or 103.7°F. Weight loss for all three events was directly related to the increase in temperature (r = 0.58), a relationship demonstrated in other studies (8).
Costill and Fox (11) determined maximal oxygen uptake (V˙O2max) in six runners before the 1968 race to estimate their intensity of effort. The subjects included Amby Burfoot (1968 winner), Ed Winrow (11th place), Tom Osler (23rd place), Tom Corbitt (43rd place and future President of the Road Runners Club of America), Lou Castagnaldo (45th place) (13), and Hal Higdon (author of Boston: A Century of Running). Their average V˙O2max was 71.4 mL·kg−1·min−1, and they used 74.8% of their maximum running the race. Lactate increased only at the end of the race, and generally in response to a finishing sprint. This contradicted conventional view that fatigue during marathons was related to lactic acid accumulation.
Three other reports (7,12,14) during this period were not performed using the race itself, but its most famous participant, Clarence DeMar. DeMar won seven Boston races (12). He had undergone six separate physiologic examinations (14) at the Harvard Fatigue Laboratory, the premier exercise physiology laboratory of this time. DeMar died of metastatic rectal carcinoma at age 70. His autopsy, reported by Currens and White (12), demonstrated coronary arteries two to three times the normal diameter. This report is often cited as evidence that exercise increases coronary caliber. Examination of the heart was difficult because the embalming trocar had pierced the heart in several places (12). This suggests that the necropsy was an afterthought and likely occurred because of Dr. White's interest in exercise.
STUDIES 1970 TO 1980
Publications (25,29,40,42,44,45,49,52) in this period are noteworthy for four reasons. First, Dr. Kenneth Cooper coauthored an article on serum electrolytes (49) and another documenting a threefold increase in cortisol and a nearly sixfold increase in aldosterone levels (42).
Second, Green et al. (25) published the first report at Boston of a cardiac arrest, anterior myocardial infarction, and subsequent death in the 1973 race. The autopsy showed only minimal coronary artery atherosclerosis. These findings predated the present knowledge that most acute cardiac events occur at non-flow-limiting atherosclerotic plaques and that autolysis of obstructing thromboses can occur.
Third, Dr. Terrance Kavanaugh et al. (29) reported on eight male cardiac patients from the Toronto Cardiac Rehabilitation Program who ran the 1973 race. They were escorted by resuscitation teams in cars. Seven men finished. That cardiac patients could run a marathon was a revolutionary concept at the time.
Fourth, Dr. Arthur Siegel et al. (52) published the first of multiple publications using members of the American Medical Joggers Association (AMJA), the predecessor of the American Medical Athletic Association (AMAA). Fifty participants provided urine samples before and 2 h after the 1978 race. Nine showed gross (n = 1) or microscopic hematuria after the race. Eight had cleared all blood by 48 h, whereas one physician had persistent slight hematuria demonstrating that athletic pseudonephritis is generally self-limited and benign.
Perhaps the most important event during the 1970s, the 1976 race or the "Run for the Hoses," was barely addressed in the medical literature. The temperature at the start was 37.2°C (45). The number of heat-injured runners prompted the formation of a more formal medical coverage team in 1978 (3). Dr. Marvin Adner has served as medical race director since 1978, assisted with many of the Boston medical studies, and retired as director after the 2006 event. (Dr. Adner, personal communication). In the only medical report of the event, Dr. Thomas O'Donnell (45) noted that heat stroke could be present despite continued sweating, a concept not widely recognized previously (45).
STUDIES 1980 TO 1990
The availability of research subjects from the AMJA, the support provided by formal medical race coverage, and the growth of marathoning as a participation sport facilitated the 41 Boston medical studies (63% of total) from 1980 onward.
Dr. Adner and Dr. William Castelli of the Framingham Heart Study (1) confirmed Dr. Peter Wood's original observation (72) of higher levels of HDL cholesterol (HDL-C) in endurance athletes. A subsequent study showed additional increases in HDL-C with modest alcohol intake (70).
Siegel et al. (58) examined creatine kinase (CK) levels in the 1979 race. Average CK levels increased further from 161 (normal < 100 U·L−1) before to 3424 U·L−1 the day after the race. Results from Boston may not be readily applicable to other endurance events. The Boston course, despite its infamous Newton and "Heartbreak" hills, actually declines a total of 448 ft (13). Downhill running is an "eccentric exercise," in which the muscle contracts while being stretched and is especially damaging to the skeletal muscle. Skeletal muscle-derived CK increases may be greater at Boston than in other events because of this eccentric component. Another study demonstrated that 8.3% of the CK was caused by the myocardial isoform (CK-MB) suggesting myocardial injury (56). Technetium 99m pyrophosphate myocardial scans 24 to 48 h after the race (56) and myocardial imaging in runners who were injected with thallium at the finish line and promptly transported to the Brigham and Women's Hospital for imaging (57) failed to show myocardial ischemia. CK-MB is the developmental form of CK and is expressed in embryonal muscle (56,66) and may be produced in satellite cells that repair muscle. Skeletal muscle CK-MB increases during marathon training and CK-MB is present in distance runners' skeletal muscle (66). Consequently, it is likely that exercise training injures skeletal muscle (as evidenced by the increased pre-exercise CK ) and that the repair process recruits satellite repair cells containing CK-MB, which is released when muscle is injured by the marathon.
McMahon et al. (38) demonstrated guaiac-positive stools after the race in 7 of 32 AMJA marathoners. This was attributed to splanchnic vasoconstriction and intestinal ischemia, a suggestion supported by subsequent Boston case reports of ischemic colitis in Boston runners (33,37,51). Runners with positive samples were younger and ran faster suggesting that the sympathetic vasoconstriction and blood flow redistribution required for more intense effort produced intestinal ischemia and fecal blood loss. "Runners' anemia" had previously been attributed to plasma volume expansion and march hemolysis.
STUDIES 1990 TO 2000
There were only six studies in this decade (9,37,54,55,60,62). Most notably, Siegel et al. (54) used antimyosin imaging to confirm normal myocardial scintigraphic images in runners with increases in cardiac troponin T (cTnT) and I (cTnI) after the race.
STUDIES 2000 TO PRESENT
Reports from the last 7 yr have addressed ischemic colitis in female runners (33,51), climatic factors affecting marathon performance (17,18,48), and changes in prostate-specific antigen (PSA) levels (31). Because cycling is known to increase PSA levels, AMAA marathoners were used to examine the effect of prolonged exercise on PSA without direct prostate trauma. Average PSA levels did not change, but 2 of the 18 subjects had elevated PSA levels (>4 ng·mL−1) at 4 and 24 h after the race, suggesting that endurance exercise can increase PSA levels in some individuals. The most important articles since 2000, however, examined exercise-associated hyponatremia (EAH) and possible cardiac injury.
EAH was first reported in 1985 in runners in the Comrades 90-km ultramarathon and the Durban Triathlon (43). Rapid-onset hyponatremia can produce pulmonary and cerebral edema, coma, and seizures (43), and it has caused death in two female marathoners in the 2002 Boston and Marine Corps races (61). Almond et al. (4) in 2002 analyzed postrace serum samples in 488 participants. EAH (serum sodium values ≤135 mmol·L−1) was found in 13% of the runners after the race. Three (0.6%) had values ≤120 mmol·L−1. On multivariate analysis, EAH was directly related to weight gain, increased race time, and BMI <20 kg·m−2. The authors suggested that excessive fluid intake was primarily responsible.
A subsequent report concluded that EAH was due to inappropriate arginine vasopressin (AVP) secretion (61). AVP was detectable in 7 of 16 runners with EAH, although AVP should be undetectable with hyponatremia and hypo-osmolality. Even with inappropriate AVP levels, hyponatremia could not develop without increased fluid intake. The opportunity for excessive fluid intake is increased in ultramarathons and in slower recreational runners. Both women who died at the Boston and Marine Corps races were running as charity fund-raisers (61). Such runners are not required to meet the qualifying times required at Boston. In the 2003 race, the first finisher with EAH finished in 4h35min (32), almost 2.5 h after the winner.
The mechanism for inappropriate AVP is unclear, but interleukin-6 (IL-6) is released from muscle during exercise (46) and can increase AVP secretion (61). Genetic factors may also contribute. One Boston runner with a sodium <120 mmol·L−1 had "mild cystic fibrosis" (2), a disease known to increase the sodium content of sweat, suggesting that some athletes may secrete "salty sweat" thereby increasing their risk for water intoxication. Inappropriate AVP could also explain why nonsteroidal anti-inflammatory drugs (NSAID) seem to be common among EAH victims (26,61) because NSAID enhance renal AVP activity (61). Intravenous 3% sodium chloride is now the standard treatment of acute EAH (61), in part because of research performed at Boston.
Nine of the 21 articles published after 2000 address serum and/or imaging markers of possible myocardial injury. C-reactive protein (CRP), von Willebrand factor, D-dimer, and fibrinolytic activity more than doubled 4 h after the 1996-2001 races, whereas fibrinogen levels decreased (59). Platelet aggregation also increased after exertion (59). Matrix metalloproteinase-9 (MMP-9) activity, a possible risk marker for acute coronary syndrome (ACS) and brain-type natriuretic peptide (BNP), a marker of heart failure severity increased immediately after the 2005 race (50). Myeloperoxidase (MPO) activity may identify patients at risk for ACS earlier than traditional markers (39). MPO levels increased in 22 of 24 subjects immediately after the 2005 race, and 14 subjects' values exceeded the manufacturer's recommended clinical threshold for diagnosing ACS (39). Both MMP and MPO are present in white blood cells, however, so increased levels may simply reflect the exercise leukocytosis noted by others (6,34) a century ago. Nevertheless, such results demonstrate the difficulty of diagnosing ACS in athletes after prolonged exertion.
Six articles examined cTn, the clinical standard for myocyte necrosis and ACS. Both cTnT (19,39,41,50,53) and cTnI (19,30,53) increased after the race. Among 482 runners in the 2002 race, 68% demonstrated elevated cTnT and cTnI levels, and 11% had values "diagnostic" of myocardial infarction, demonstrating elevations in cardiac markers in the absence of ACS. Runners with no prior marathon experience where three times more likely to increase cTn.
Neilan et al. (41) measured serological markers of myocardial injury and used echocardiographic markers of myocardial performance in the 2004-2005 races. Early transmitral filling velocities decreased and late filling increased immediately after the race, suggesting left ventricular diastolic dysfunction. The change in right ventricular area decreased, suggesting reduced right ventricular performance. cTnT increased above the 99th percentile after the race in 63% of the participants and 47% had cTnT levels consistent with myocardial necrosis. N-terminal pro-brain natriuretic peptide (NT-proBNP) concentrations doubled. The increases in myocardial serological markers correlated directly with measures of myocardial dysfunction and inversely with the number of miles run per week. Runners training <35 miles weekly had worse myocardial performance and higher serologic markers of myocardial injury. The authors suggested that runners with less training are more vulnerable to cardiac injury. An accompanying editorial cautioned against concluding that marathoning produces actual myocardial injury because there is no evidence that former endurance athletes experience more cardiac dysfunction (66).
The 66 Boston articles identified must be among the largest number from a single athletic event. Boston medical studies not only provide lessons applicable to medically managing modern athletes but also demonstrate the interests and concerns of researchers who have used the Boston Marathon for more than a century to study the effects of prolonged exercise. Advances in the understanding and treatment of marathon complications such as EAH are major accomplishments produced by medical researchers interested in the marathon and the runners who participated in these studies.
The results of the present review do not constitute endorsement by ACSM.
1. Adner MM, Castelli WP. Elevated high-density lipoprotein levels in marathon runners. JAMA
2. Adner MM, Gembarowicz R, Casey J, et al. Point-of-care biochemical monitoring of boston marathon runners: a comparison of prerace and postrace controls to runners requiring on-site medical attention. Point of Care: The Journal of Near-Patient Testing & Technology
3. Adner MM, Scarlet JJ, Casey J, Robinson W, Jones BH. The Boston Marathon Medical Care Team: Ten years of experience. The Physican and Sports Medicine
4. Almond CS, Shin AY, Fortescue EB, et al. Hyponatremia among runners in the Boston Marathon. N Engl J Med
5. Behrman RA. Urinary findings before and after a marathon race. N Engl J Med
6. Blake JB, Larrabee RC. Observations upon long-distance runners. Boston Medical and Surgical Journal
7. Bock AV. The circulation of a marathoner. J Sports Med Phys Fitness
8. Buskirk ER, Beetham WP Jr. Dehydration and body temperature as a result of marathon running. Medicina Sportiva
9. Conlay LA, Sabounjian LA, Wurtman RJ. Exercise and neuromodulators: choline and acetylcholine in marathon runners. Int J Sports Med
. 1992;13(Suppl 1):S141-2.
10. Conlay LA, Wurtman RJ, Blusztajn K, Coviella IL, Maher TJ, Evoniuk GE. Decreased plasma choline concentrations in marathon runners. N Engl J Med
11. Conlay LA, Wurtman RJ, Lopez G-C, et al. Effects of running the Boston marathon on plasma concentrations of large neutral amino acids. J Neural Transm
12. Costill DL, Bowers R, Branam G, Sparks K. Muscle glycogen utilization during prolonged exercise on successive days. J Appl Physiol
13. Costill DL, Fox EL. Energetics of Marathon Running. Medicine and Science in Sports
14. Currens JH, White PD. Half a century of running. Clinical, physiologic and autopsy findings in the case of Clarence DeMar ("Mr. Marathon"). N Engl J Med
15. Derderian T. Boston Marathon: The First Century of the World's Premier Running Event
. Champaign, IL Human Kinetics 1995.
16. Dill DB. Marathoner DeMar: physiological studies. J Natl Cancer Inst
17. Douglas PS, O'Toole ML, Hiller WD, Hackney K, Reichek N. Cardiac fatigue after prolonged exercise. Circulation
18. Edmondstone WM. Cardiac chest pain: does body language help the diagnosis. BMJ
19. Ely MR, Cheuvront SN, Montain SJ. Neither Cloud Cover nor Low Solar Loads Are Associated with Fast Marathon Performance. Med Sci Sports Exerc
20. Ely MR, Cheuvront SN, Roberts WO, Montain SJ. Impact of weather on marathon-running performance. Med Sci Sports Exerc
21. Farkas TA, Zane RD. Comminuted femur fracture secondary to stress during the Boston marathon. J Emerg Med
22. Fortescue EB, Shin AY, Greenes DS et al. Cardiac Troponin Increases Among Runners in the Boston Marathon. Ann Emerg Med
23. Gilligan DR, Altschule MD, Katersky EM. Physiological Intravascular Hemolysis of Exercise. Hemoglobinemia and Hemoglobinuria Following Cross-Country Runs. Journal of Clinical Investigation
24. Gordon B. The Effect of Effort on the Size of the Heart. Observations on Animals and Marathon Runners. American Journal of Roentgenology
25. Gordon B. Effect of Exercise on the Circulation, Sugar Metabolism and Other Factors. Northwest Medicine
26. Gordon B. Effects of Exercise on Circulation and Respiration. Journal of the Medical Society of New Jersey
27. Gordon B, Kohn LA, Levine SA, Matton M, Scriver WdM, Whiting WB. Sugar content of the blood in runners following a marathon race with special reference to the prevention of hypoglycemia: further observations. Journal of the American Medical Association
28. Gordon B, Levine SA, Wilmaers A. Observations on a group of marathon runners with special reference to the circulation. Archives of Internal Medicine
29. Green LH, Cohen SI, Kurland G. Fatal myocardial infarction in marathon racing. Ann Intern Med
30. Irving RA, Noakes TD, Buck R, et al. Evaluation of renal function and fluid homeostasis during recovery from exercise-induced hyponatremia. J Appl Physiol
31. Isaacs R, Gordon B. The effect of exercise on the distribution of corpuscles in the blood stream. American Journal Physiology
32. Jessen N, Goodyear LJ. Contraction signaling to glucose transport in skeletal muscle. J Appl Physiol
33. Kavanagh T, Shephard RH, Pandit V. Marathon running after myocardial infarction. JAMA
34. Knapp PC, Thomas JJ. The Reflexes in Long-Distance Runners. A Study of the Influence of Fatigue upon Certain Reflexes. Journal Nervous and Mental Disease
35. Kratz A, Lewandrowski KB, Siegel AJ, et al. Effect of marathon running on hematologic and biochemical laboratory parameters, including cardiac markers. Am J Clin Pathol
36. Kratz A, Lewandrowski KB, Siegel AJ, et al. Effect of marathon running on total and free serum prostate-specific antigen concentrations. Arch Pathol Lab Med
37. Kratz A, Siegel AJ, Verbalis JG, et al. Sodium status of collapsed marathon runners. Arch Pathol Lab Med
38. Kratz A, Wood MJ, Siegel AJ, Hiers JR, Van Cott EM. Effects of marathon running on platelet activation markers: direct evidence for in vivo platelet activation. Am J Clin Pathol
39. Kyriakos R, Siewert B, Kato E, Sosna J, Kruskal JB. CT findings in runner's colitis. Abdom Imaging
40. Larrabee R. Leucocytosis after violent exercise. Journal of Medical Research
41. Levine SA. The myth of strict bed rest in the treatment of heart disease. Am Heart J
42. Levine SA, Gordon B, Derick CL. Some changes in the chemical constituents of the blood following a marathon race with special reference to the development of hypoglycemia. Journal of the American Medical Association
43. Lucas W, Schroy PC III. Reversible ischemic colitis in a high endurance athlete. Am J Gastroenterol
44. Maresh CM, Allison TG, Noble BJ, Drash A, Kraemer WJ. Substrate and hormone responses to exercise following a marathon run. Int J Sports Med
45. McMahon LF, Jr., Ryan MJ, Larson D, Fisher RL. Occult gastrointestinal blood loss in marathon runners. Ann Intern Med
46. Melanson SE, Green SM, Wood MJ, Neilan TG, Lewandrowski EL. Elevation of myeloperoxidase in conjunction with cardiac-specific markers after marathon running. Am J Clin Pathol
47. Myers KJ. Marathon running and vision. J Am Optom Assoc
48. Neilan TG, Januzzi JL, Lee-Lewandrowski E, et al. Myocardial injury and ventricular dysfunction related to training levels among nonelite participants in the Boston marathon. Circulation
49. Neilan TG, Yoerger DM, Douglas PS, et al. Persistent and reversible cardiac dysfunction among amateur marathon runners. Eur Heart J
50. Newmark ST, Himathongkam T, Martin RP, Cooper KH, Rose LI. Adrenocortical response to marathon running. J Clin Endocrinol Metab
51. Noakes TD, Goodwin N, Rayner BL, Branken T, Taylor RK. Water intoxication: a possible complication during endurance exercise. Med Sci Sports Exerc
52. Noble BJ, Maresh CM, Allison TG, Drash A. Cardio-respiratory and perceptual recovery from a marathon run. Medicine and Science in Sports
53. O'Donnell TF Jr. The hemodynamic and metabolic alterations associated with acute heat stress injury in marathon runners. Ann N Y Acad Sci
54. Pedersen BK. IL-6 signalling in exercise and disease. Biochem Soc Trans
55. Poortmans J, Jeanloz RW. Quantitative immunological determination of 12 plasma proteins excreted in human urine collected before and after exercise. J Clin Invest
56. Roberts WO. Heat and cold: what does the environment do to marathon injury. Sports Med
57. Rose LI, Carroll DR, Lowe SL, Peterson EW, Cooper KH. Serum electrolyte changes after marathon running. J Appl Physiol
58. Rubin CT, Pratt GW, Porter AL, Lanyon LE, Poss R. The use of ultrasound in vivo to determine acute change in the mechanical properties of bone following intense physical activity. J Biomech
59. Saenz AJ, Lee-Lewandrowski E, Wood MJ, et al. Measurement of a plasma stroke biomarker panel and cardiac troponin T in marathon runners before and after the 2005 Boston marathon. Am J Clin Pathol
60. Sanchez LD, Tracy JA, Berkoff D, Pedrosa I. Ischemic colitis in marathon runners: a case-based review. J Emerg Med
61. Shin AY, Almond CS, Mannix RC, et al. The Boston Marathon Study: a novel approach to research during residency. Pediatrics
62. Siegel AJ, Hennekens CH, Solomon HS, Van Boeckel B. Exercise-related hematuria. Findings in a group of marathon runners. JAMA
63. Siegel AJ, Lewandrowski EL, Chun KY, Sholar MB, Fischman AJ, Lewandrowski KB. Changes in cardiac markers including B-natriuretic peptide in runners after the Boston marathon. Am J Cardiol
64. Siegel AJ, Lewandrowski KB, Strauss HW, Fischman AJ, Yasuda T. Normal post-race antimyosin myocardial scintigraphy in asymptomatic marathon runners with elevated serum creatine kinase MB isoenzyme and troponin T levels. Evidence against silent myocardial cell necrosis. Cardiology
65. Siegel AJ, Sholar M, Yang J, Dhanak E, Lewandrowski KB. Elevated serum cardiac markers in asymptomatic marathon runners after competition: is the myocardium stunned. Cardiology
66. Siegel AJ, Silverman LM, Evans WJ. Elevated skeletal muscle creatine kinase MB isoenzyme levels in marathon runners. JAMA
67. Siegel AJ, Silverman LM, Holman BL. Elevated creatine kinase MB isoenzyme levels in marathon runners. Normal myocardial scintigrams suggest noncardiac source. JAMA
68. Siegel AJ, Silverman LM, Holman BL. Normal results of post-race thallium-201 myocardial perfusion imaging in marathon runners with elevated serum MB creatine kinase levels. Am J Med
69. Siegel AJ, Silverman LM, Lopez RE. Creatine kinase elevations in marathon runners: relationship to training and competition. Yale J Biol Med
70. Siegel AJ, Stec JJ, Lipinska I, et al. Effect of marathon running on inflammatory and hemostatic markers. Am J Cardiol
. 2001;88:918-20, A9.
71. Siegel AJ, Stewart EL, Barone B. Body image assessment and eating attitudes in marathon runners: inverse findings to patients with anorexia nervosa. Annals of Sports Medicine
72. Siegel AJ, Verbalis JG, Clement S, et al. Hyponatremia in marathon runners due to inappropriate arginine vasopressin secretion. Am J Med
73. Takahashi M, Lee L, Shi Q, Gawad Y, Jackowski G. Use of enzyme immunoassay for measurement of skeletal troponin-I utilizing isoform-specific monoclonal antibodies. Clin Biochem
74. Thijssen DH, Vos JB, Verseyden C, et al. Haematopoietic stem cells and endothelial progenitor cells in healthy men: effect of aging and training. Aging Cell. 2006;5:495-503.
75. Thomas D. Echocardiographic findings in athletes. In: Thompson PD. Exercise and Sports Cardiology. New YorkMcGraw-Hill. 2000;43-701.
76. Thompson PD. D. Bruce Dill Historical lecture. Historical concepts of the athlete's heart. Med Sci Sports Exerc
77. Thompson PD, Apple FS, Wu A. Marathoner's heart. Circulation. 2006;114:2306-8.
78. Trapasso LM, Cooper JD. Record performances at the Boston Marathon: biometeorological factors. Int J Biometeorol
79. Warhol MJ, Siegel AJ, Evans WJ, Silverman LM. Skeletal muscle injury and repair in marathon runners after competition. Am J Pathol
80. White P. Bradycardia (below rate of 40) in athletes, especially long distance runners. JAMA
81. White PD. The Pulse after a Marathon Race. Journal of American Medical Association
82. Willett W, Hennekens CH, Siegel AJ, Adner MM, Castelli WP. Alcohol consumption and high density lipoprotein cholesterol in marathon runners. N Engl J Med
83. Williams H, Arnold H. The Effects of violent and prolonged muscular exercise upon the heart. The Philadelphia Medical Journal. 1899;1233-9.
84. Wood PD, Haskell W, Klein H, Lewis S, Stern MP, Farquhar JW. The distribution of plasma lipoproteins in middle-aged male runners. Metabolism. 1976;25:1249-57.
This article has been cited 1 time(s).
Medicine & Science in Sports & ExerciseErratum RetractionMedicine & Science in Sports & Exercise
ENDURANCE; EXERCISE; ATHLETE'S HEART; CARDIOMEGALY; TROPONIN
©2009The American College of Sports Medicine
Highlight selected keywords in the article text.