Cardiovascular effects of training for a marathon run in unfit middle aged men.

Abstract

The effects of a 30 week exercise programme on serum lipid values, blood pressure, and cardiac function were assessed in a group of sedentary men aged 35-50 training for their first marathon. Mean serum cholesterol concentration (n=33) fell by 12% from 6-54 (SE 0.18) to 5-76 (0-15) mmol/l (mean fall mmol/l; 95% confidence interval 0-52 to 1-04 mmoVIl), serum triglyceride concentration (n=33) by 22% from 156 (0.17) to 1-21 (0-09) mmol/l (mean fall 0 34 mmol/l; 95% confidence interval 0-12 to 056 mmol/l), and mean blood pressure (n=27) by 10% from 102 (2) ventricular end-diastolic volume (n= 16) increased with training; as a result of this and an increased exercise left ventricular ejection fraction peak exercise cardiac output increased from 19.9 (1-2) to 23-1 (3-0) I/min (mean rise 3-2 I/min; 95% confidence interval 1-5 to 5-0 I/min). Maximum oxygen consumption increased from 33-9 (1.6) to 39-0 (1.3) ml/kg/min (mean rise 5-0 ml/kg/min; 95% confidence interval 1-8 to 8.2 ml/kg/min).This study showed favourable effects on coronary risk factors and cardiac function and supports the place ofregular exercise in coronary prevention programmes. IntroductionThe sight of runners on the streets of Britain has become commonplace. This burgeoning of interest has been most evident in nonathletes and is reflected in the number of popular marathons that have taken place in recent years. It is interesting to speculate on the motives behind this activity, though it is a popular belief that exercise is good for the individual and especially for the heart. Though much is known about the effect of training on cardiorespiratory function in athletes, thereis littleinformation concerning the benefits (or otherwise) of prolonged endurance training in previously unfit runners, many of whom are middle aged. Indeed, concern has been expressed about the possible hazards of prolonged exercise in this age group, given the reports of sudden death in marathon runners.

Left Ventricular Function at Rest, during Exercise and Recovery Period in Trained Athletes: Assessment with Radionuclide Angiography

“…Contro versy exists concerning left ventricular end-diastolic vol ume during dynamic exercise. Our results seemed to indicate a negligible increase in EDVI during exercise in athletes tested in a supine position, as reported by other studies [8,15], in contrast to others [16,17]. In un trained healthy subjects the increase in EF seems to be associated with an increased end-diastolic volume simi lar at both E-I and E-II [5]; other authors [13,14] report a raised end-diastolic volume only during the E-I.…”

Exercise in cardiac rehabilitation.

“…The eVects of exercise training on weight loss in obese cardiac subjects are disappointing, 84 but some controlled trials of cardiac rehabilitation have shown a weight loss in the treated group. 85 However, a failure to reduce body weight may be due to an increase in lean muscle mass rather than a failure to reduce body fat, 86 and this has also been found in controlled trials. 87 If the patient takes a great deal of exercise, equivalent to running 15 or more miles a week, weight loss is likely.…”

Effects of Long-Term Exercise of Moderate Intensity on Anthropometric Values and Serum Lipids and Lipoproteins

“…Longitudinal studies of individuals exercising on a recreational basis have yielded less marked results, which are often difficult to interpret due to confounding factors like length of the training period, intensity and form of the training programme and diet or weight loss of the individuals under investigation (14)(15)(16)(17)(18)(19)(20). Furthermore, most of these studies are restricted to either exercising males or -to a far lesser extent -exercising females (17)(18)(19)(20). The present study is designed to investigate the effects of a prolonged training programme of moderate intensity on the lipid status in a group of previously sedentary males and females, while keeping other habitual factors constant.…”