Sudden death and physical activity in athletes and nonathletes.

Among young athletes, sudden deaths are predominantly associated with cardiomyopathies, coronary artery abnormalities and myocarditis, but coronary heart disease is a reality already in this group. The absolute risk of sudden death is, however, low and the benefits of routine medical screening are small. If an athlete has had any symptoms that arouse suspicion of cardiac disease, the athlete must be meticulously investigated, as an underlying life-threatening illness may be present. Among all nonathletes, as well as athletes > or = 30 years, the predominant cause of sudden death is coronary heart disease. A large number of studies have provided strong evidence suggesting the benefits of physical activity regarding prevention of cardiovascular death and disease. The immediate risk for sudden death is higher during physical activity than during other times, especially among usually sedentary individuals, but inactivity is much more dangerous in the long run. Regular exercise at moderate intensity gives large benefits with small risks. The benefits of irregular and intensive exercise are less clear and the risks higher. For the individual without known heart disease who exercises regularly, the risk for sudden death during physical activity is extremely small.