Physiological and medical aspects of strenuous mass sport events

This review summarizes the main features to be considered previous to and during the performance of strenuous, prolonged mass sport events. At the present time the best predictors of one's ability to endure the effort are probably not physiological tests but detailed information of one's health status and exercise habits in relation to the type, duration, and intensity of the event. The preparation for high-intensity events lasting 1 1/2 hours or more should include filling of the glycogen stores of the most taxed muscles by proper supercompensation techniques. During and even immediately prior to prolonged activities, largely irrespectively of their intensity, it is advisable to ingest small amounts of easily absorbable carbohydrate, best as fluid, latest after 1 1/2 hours of exercise, and every 20-30 min thereafter. Fluid loss should be kept in minimum by drinking 150-200 ml at a time 3 to 4 times per hour. This is of ultimate importance in warm and hot weather. In cold especially middle-aged and older persons should pay special attention to avoid excessive intensity of effort during the first 15 min of exercise, and to protect the most cold sensitive parts of the body, like head and neck, in order to avoid reflex increase of circulatory stress. Serious health risks of mass sport events have been shown to be small, when factors causing excessive acute, circulatory load are avoided. Therefore, exercise during or shortly after acute or febrile illness, start of exercise without sufficient warm-up especially in cold, sudden or maximal bursts of activity, exercise loaded with strong emotions, exercise after heavy meal or alcohol intake, and smoking during exercise should be avoided.