Over the last decade the culture of physical exercise has changed. While elite athletes are training to ever more rigorous schedules, our middle aged sedentary population, no doubt seeing the writing on the wall, are hurrying to sign up for the fashionable, local fitness centres. When talking about athletes' hearts, we must distinguish between elite athletes, recreational sports men and women, non-athletes who wish to maintain cardiovascular fitness, and athletic patients with known cardiovascular disease. This article is mainly about athletes with serious sporting ambitions at club or higher level, who train most days for more than one hour. I will make it clear when I am referring to other types of athletes.

A regular training programme causes favourable changes in skeletal muscle performance (the realm of the sports physiologist) and two clear cut cardiovascular effects—namely, enlargement of the heart and a slow pulse rate at rest. These are the components of a characteristic clinical picture known as the “athlete's heart”.1

Athletes, as a group, tend to be somewhat introspective about their health and will frequently consult doctors complaining of palpitations, dizziness, fatigue, chest pain, and undue dyspnoea. Physical examination may reveal some unusual signs, which will do little to reassure the doctor, already aware of widely publicised high profile cases of sudden death in association with sporting activity. The finding of an apparently abnormal ECG will cause further anxiety. A knowledge of the characteristic features of the athlete's heart is therefore important if the patient is to be advised wisely.2