Group Of Marathon Runners Research Articles

P352 NITRIC OXIDE IS DIFFERENTIALLY INVOLVED IN EXERCISE-INDUCED BRONCHOSPASM IN MARATHON RUNNERS

The role of nitric oxide (NO) in bronchospasm is still controversial. While asthmatic patients present bronchospasm-induced by exercise (BIE) ranging between 70-90%, non-asthmatic individuals present 10-15%. In addition, professional athletes without asthma, depending on the sports’ modalities can present 18-70% of BIE. Thus, marathon runners (MR) are a group of athletes presenting high rates of BIE, although there is still a group of marathon runners who does not present BIE.

Is marathon running toxic? An observational study of cardiovascular disease prevalence and longevity in 54 male marathon runners

ABSTRACTObjectives: Recent literature suggests reduced benefits associated with high intensity (HIT) and or sustained intensity exercise training (SIT). While important, they tend to contrast with other studies of HIT and SIT and may not be representative of all individuals wishing to participate in activities such as marathon running. The purpose of this observational report is to describe a 45-year history of 54 long distance runners, their incidence of death from cardiovascular disease and their ages at death compared to the normal population.Methods: Data were collected longitudinally on all 54 members of a Southern California mens running club by the author, a cardiologist with 45 years of experience, member of the running club, and personal physician for most of the men for over 40 years. Retrospective and observational data were collected from direct professional and personal contact with the 54 men in the running club.Results: Closely monitored group of marathon runners with extreme HIT and SIT revealed a low incidence of cardiovascular disease (CVD) with an extended longevity relative to the general population.Conclusion: The benefits of exercise for reducing risk of chronic disease, including CVD, are well known. Whether these benefits extend to the more intense and prolonged exercise associated with marathon running is unclear. However, as evidenced in the observational data presented here, at least in some populations, years of high-intensity, prolonged exercise may not be as toxic as suggested by others. Whether this is due to self-selection or predisposition is not well understood but merits further study.

Long-Termendurance Sport Practice Increases The Incidence Of Lone Atrial Fibrillation Inmen: A Follow-Up Study.

A retrospective cohort study was designed witha group of 252 marathon runners recruited in 199092 and a population sample of305 sedentary men recruited in 1994-96. The physical activity was evaluatedwith the Minnesota leisure time physical activity questionnaire. At therecruitment moment, a physical examination, a BP measure and an ECG wereperformed in all men. A maximal exercise test and an echocardiogram wasobtained only in the marathon runners. They were all contacted in 2002-03 andinvited to attend an outpatients clinic to identify suggestive symptoms ofhaving experienced an arrhythmia requiring medical attention. In those withsuggestive symptoms of atrial fibrillation, medical records were reviewed.Finally, LAF was diagnosed on the basis of the presence of atrial fibrillationin an electrocardiogram in the absence of structural heart disease and otheridentifiable cause of arrhythmia (i.e. alcohol, hyperthyroidism). In the groupof marathon runners, a second two-dimensional echocardiogram was obtained atthe end of the follow up. Moreover, a new questionnaire to access the lifetimetotal physical activity practice was administered.

Long-term endurance sport practice increases the incidence of lone atrial fibrillation in men: a follow-up study

The aim of this study is to determine the incidence of lone atrial fibrillation (LAF) in males according to sport practice and to identify possible clinical markers related to LAF among marathon runners. A retrospective cohort study was designed. A group of marathon runners (n = 252) and a population-based sample of sedentary men (n = 305) recruited in 1990-92 and 1994-96, respectively, were contacted in 2002-03 and invited to attend an outpatient clinic to identify suggestive symptoms of having experienced an arrhythmia requiring medical attention. In those with suggestive symptoms of atrial fibrillation, medical records were reviewed. Finally, LAF was diagnosed on the basis of the presence of atrial fibrillation in an electrocardiographic recording. In the group of marathon runners, an echocardiogram was performed at inclusion and at the end of the study. The annual incidence rate of LAF among marathon runners and sedentary men was 0.43/100 and 0.11/100, respectively. Endurance sport practice was associated with a higher risk of incident LAF in the multivariate age- and blood pressure-adjusted Cox regression models (hazard ratio = 8.80; 95% confidence interval: 1.26-61.29). In the group of marathon runners, left atrial inferosuperior diameter and left atrial volume were both associated with a higher risk of incident LAF. Long-term endurance sport practice is associated with a higher risk of symptomatic LAF in men. This risk is associated with a larger left atrial inferosuperior diameter and volume in physically active subjects.

Immune function in marathon runners versus sedentary controls.

Marathon runners (N = 22) who had completed at least seven marathons (X +/- SEM = 23.6 +/- 5.7) and had been training for marathon race events for at least 4 yr (12.3 +/- 1.3) were compared with sedentary controls (N = 18). Although the two groups were of similar age (38.7 +/- 1.5 and 43.9 +/- 2.2 yr, respectively) and height, the marathon runners were significantly leaner and possessed a VO2max 60% higher than that of the controls. Neutrophil counts tended to be lower in the group of marathoners, while other leukocyte and lymphocyte subsets were similar to controls. Mitogen-induced lymphocyte proliferation did not differ between groups. Natural killer cell cytotoxic activity (NKCA) was significantly higher in the marathoners versus controls (373 +/- 38 vs 237 +/- 41 total lytic units, respectively, a 57% difference, P = 0.02). For all subjects combined (N = 40) and within the group of marathon runners (N = 22), percent body fat was negatively correlated with NKCA (r = -0.48, P = 0.002; r = -0.49, P = 0.019, respectively), and age was negatively correlated with Con A-induced lymphocyte proliferation (r = -0.41, P = 0.009; r = -0.53, P = 0.011, respectively). These data indicate that NKCA but not mitogen-induced lymphocyte proliferation is higher in marathon runners relative to sedentary controls.

Food Intake Patterns of Marathon Runners

A group of marathon runners (290 males, 54 females, mean age 39.7 +/- 0.7 years) who participated in the Los Angeles Marathon recorded their food and fluid intake throughout a 3-day period, with the time of day denoted for each entry. Investigators coded each subject's food intake according to six time periods: 5:00-8:59 a.m., 9:00-10:59 a.m., 11:00 a.m.-1:59 p.m., 2:00-3:59 p.m., 4:00-7:59 p.m., and 8:00 p.m.-4:59 a.m. The average intake of the runners consisted of 314 +/- 6 g (52.3%) carbohydrates, 83.2 +/- 2.0 g (30.7%) fat, and 99.7 +/- 2.3 g (16.5%) protein. Time periods for breakfast (13.7%), lunch (23.8%), and supper (34.0%) accounted for 71.5% of total caloric intake, with snack time periods contributing 28.5%. Breakfast calories were 68.9 +/- 0.9% carbohydrate and 20.4 +/- 0.7% fat in contrast to supper calories, which were 47.7 +/- 0.8% and 31.8 +/- 0.6%, respectively. A sizable proportion of the daily caloric intake of recreational marathon runners is contributed by snacks and food intake after 4:00 p.m.

Marathon runners presented lower serum cholesteryl ester transfer activity than sedentary subjects

Acute exercise promotes raised HDL cholesterol concentrations by lipolysis stimulation, but this effect is insufficient to explain the more permanent HDL increases seen during regular exercise. During training periods in a group of marathon runners, we measured lipid transfer protein I (LTP-I)-mediated cholesteryl ester transfer activity (CETA) and its relationship to their HDL concentrations. Runners of both sexes showed significantly lower CETA values than those of sedentary controls. Male runners also had significantly lower serum concentrations of triglyceride, VLDL cholesterol and apolipoprotein B, and significantly higher concentrations of HDL cholesterol and apolipoprotein A-I than male controls. Results indicate that regular practice of aerobic exercise promotes modifications of lipoprotein metabolism related not only to lipolysis, but also to lower CETA. Such modifications are associated with reduced risk of atherosclerosis.

Creatine Kinase Activity Following Strenuous Exertion-Reply

<h3>In Reply.—</h3> The values for total CK activity observed by Brown et al are consistent with the prerace and postrace serial values for total CK activity reported by us in a group of marathon runners.¹We observed a mean postrace total creatine kinase level of 3,424 units/L in 15 runners after the 1979 Boston Marathon.¹These samples were obtained roughly 24 hours after the completion of the race, which corresponded to the peak values as determined in a subgroup of subjects tested more frequently. The postrace peaks in total serum CK activity ranged widely from twice that of normal (319 units/L) to almost 100 times normal (9,260 units/ L). The extraordinarily high values seemed to cluster in high-achieving recreational-type runners who had undertrained in terms of weekly mileage for the maximal effort expended in the race. These values represent considerable transient exertional rhabdomyolysis, with persistent abnormal creatine kinase

Onset of blood lactate accumulation and enzyme activities in m. vastus lateralis in man.

In an earlier study, we reported close relationships between marathon running performance and the running velocity (V) at which the "onset of blood lactate accumulation" (VOBLA) occurs in a group of marathon runners. Using biopsy material from the m. vastus lateralis of the same subjects (n = 19), we have evaluated the relationship of VOBLA to different muscle enzyme activities together with muscle fiber composition and capillary density in the present study. The activities of lactate dehydrogenase (LDH EC 1.1.1.27), phosphofructokinase (PFK EC 2.7.1.11), and citrate synthase (CS EC 4.1.3.7) were determined. VOBLA was negatively correlated to LDH (r = -0.54) and PFK/CS (r = -0.68). Using multiple regression analysis, the PFK/CS ratio together with the capillary density accounted for 61% of the variation in VOBLA. Absolute training kilometrage was the most significant variable measured and accounted for 77% of the variation in VOBLA. Subjects were divided into elite runners (n = 6) and nonelite runners (n = 13) for an additional analysis of the relationship between VOBLA and the ratios of PFK/CS or LDH/CS. Significant relationships between VOBLA and the ratios were observed only in the nonelite runners (r = -0.77 and -0.66, respectively). The vertical distances between the regression lines for these two subject groups could not be explained only on the basis of the enzyme activity ratios. A greater adaptation to fat combustion in the elite runners might explain the disproportionally high VOBLA in relation to the PFK/CS or LDH/CS activity ratios.

Exercise-related hematuria. Findings in a group of marathon runners.

Sequential urine specimens were obtained from 50 marathon runners before, immediately after, and on three successive days following a marathon race. All prerace samples were normal, but nine (18%) of the 50 postrace urinalyses showed gross (one specimen) or microscopic (eight specimens) hematuria. No formed elements other than RBCs were seen, and all abnormalities cleared by 48 hours. Exercise-related hematuria appears to be a frequent, self-limited, and benign condition. Physicians should be aware of its occurrence and reserve extended testing for cases in which abnormalities persist beyond 48 to 72 hours.