Abstract des Autors

The physical activity index of 777 male South African executives and its relation with some selected coronary risk factors was studied. The physical activity index was computed as the product of the intensity, frequency and duration of participation in physical activity during leisure time. Subjects were classified into tertials (low, moderate and high) based on their physical activity index. Subjects that expended more than 1500 kcal/week were classified as highly active, while those that expended less than 150 kcal/week were placed in the low activity group. Only 14.3% of the entire survey group expended more than 1500 kcal/week, while 61.3% reported no participation or participation at an intensity of lower than 150 kcal/week. This sedentary existence is reflected in the fact that the average physical work capacity (PWC170) of the group was 2.3 watt/kg, which is lower than the norm for adult fitness that was found to occur in the literature. High intensity participation (>/=1500 kcal/week) showed significant associations with the age, percentage body fat, PWC170, total cholesterol, HDL-cholesterol concentrations and cholesterol/HDL-ratio. After controlling for the influence of the covariables age, body mass, percentage body fat and tabacco smoking a high level of participation in physical activity (>/=1500 kcal/week) still showed significant associations with HDL-cholesterol and LDL-cholesterol concentrations as well as with the cholesterol/HDL-ratio. This suggests a possible mechanism for the protection that participation in regular physical activity shows, in some studies, against the development of coronary heart disease. It is concluded, however, that very few (14.3%) of the executives in this study were able to manage such a level of participation in physical activity during their leisure time. Verf.-Referat