Why do athletes seem prone to infection?

Some athletes appear to sustain more than their fair share of respiratory illness, although the reasons remain unclear. How should such patients be managed?

The most common respiratory illnesses in athletes are viral and bacterial infections, asthma, allergy and noninfectious inflammation. Over the past two decades, it has been recognised that there is a link between exercise load and illness, and that the risk of illness – particularly upper respiratory illness – in adolescents and adults is increased with a bout of intense exercise, or over time with an accumulation of training.