The middle-aged marathon runner.

Middle-aged runners form an appreciable number of those engaged in marathon running. They tend to have above average intelligence, high socioeconomic status, and better levels of aerobic fitness than sedentary members of the same age group. "Too much too soon" is the commonest cause of injury. Training before a marathon should last 18 months to two years. Middle-aged runners tend to experience fewer injuries than other marathoners. However, relatively minor complaints will be disastrous to them if they have to stop running. Injuries can occur from lack of warm up exercises, environmental factors such as weather, poor street lighting, carbon monoxide from car exhausts, etc. Some contraindications to marathon running are: poorly controlled diabetes, recent acute pulmonary disease, active rheumatoid arthritis, and recent cardiac conditions. Finishing a marathon involves both agony and ecstasy.