Abstract

BACKGROUND: Regular cyclists have been found to have a lower incidence of coronary events (CHD) than the general public. Non-invasive studies have found that competitive cyclists develop a cardiac hypertrophy that is physiological and reversible. METHODS: To obtain pathological support for these observations, the postmortem findings of 32 cyclists killed in accidents have been compared with those in a control group of 32 other road traffic accidents, which were matched with the cyclists by sex, age, and year of death. FINDINGS: Large myocardial scars and complete blockage of a coronary artery were only found in the controls; serious stenoses of coronary arteries (> 50%) were found in eight controls but in only one of the cyclists. Of the cyclists, 25 had normal coronary arteries as compared with 14 of the controls. The mean age of the cyclists with evidence of CHD was greater than that of similarly affected controls. The heart weights of the two groups were almost the same but heart weight varied with the degree of CHD. The heart weight of the healthy cyclists (389 g) was greater than that of the healthy controls (371 g) but this was not statistically significant. INTERPRETATION: The results are in keeping with the concept that regular exercise provides some protection from the development of CHD and that cycling may be a valuable form of exercise in this respect. This may be of importance as the number of physically active occupations declines.