[The importance of sports for the prevention of coronary heart disease--physiological and pathophysiological aspects]

Abstract

For the application of physical conditioning in the prevention of coronary heart disease to be meaningful, account must be taken of physiological and pathophysiological baselines. Physical activity is associated with an increase in metabolic rate, and the prophylactic effect of exercise is due mainly to metabolic effects and not, as commonly thought, to hemodynamic factors. Raising the metabolic rate has a positive effect on risk factors which--with the exception of smoking--are largely metabolic. For this reason, the physiological aspects of the release of energy and its increase under physical exercise are described. Of decisive importance for prophylaxis is not so much the nature of the exercise--for example endurance training in particular--as the overall extent of physical exercise, and the resulting energy consumption. The hemodynamic effect of physical activity, in particular the optimization of cardiovascular function, is of importance not so much for primary preventive reasons as for reducing the oxygen requirement of the myocardium--a secondary preventive measure. For producing a cardiovascular training effect, forms of exercise performed close to the aerobic-anaerobic threshold (AAT) are optimal. A common mistake is to assume that the training effect achieved under physiological conditions can simply be extrapolated to the pathophysiological situation. Exercise workloads that are below the aerobic-anaerobic threshold fail to produce a training effect. Here, the major aim must be to achieve metabolic, coordinative and motivational effects. If the physiological responses to exercise, in particular heart rate, are modified by pathophysiological or pharmacological mechanisms, other, in particular respiratory and metabolic parameters should be used as regulators of training. Such parameters are considered in detail.