Skip to Main Content


I’ve been feeling ill for four weeks. We thought originally it was just a virus but found out through tests that it is malaria. I don’t know when I caught it but am very glad I’m over the worst of it. I’m hoping to be back to full fitness in the next couple of weeks.

Ivory Coast and Chelsea striker Didier Drogba, quoted in, November 2010

Sportspeople are subject to the same infections as the rest of the community; however, certain circumstances in sport may increase the susceptibility of sportspeople to infections. Sportspeople involved in team sports have close contact with teammates, which increases the likelihood of spread of infection. In addition, team members often share food and drink, particularly since the increased use of squeeze bottles during exercise.

In this chapter we:

  • review the relationships between exercise/activity and infections

  • discuss whether sportspeople should exercise/train when suffering an infection

  • discuss management of a range of specific infections in athletes according to the region of presentation—skin, respiratory, gastrointestinal and liver etc.

  • outline national infection prevention strategy guidelines.

Exercise and infection

There is considerable debate regarding the relationship between exercise and infection. It is important to, firstly, consider the relationship between exercise and the immune system, and then examine whether there is an increased incidence of infection associated with intense exercise. Finally we discuss when an athlete can train and play with an infection.

Exercise and the immune system

The immune system can be considered as two complementary parts.1 First is the innate immune system, which is non-specific regarding host defense. Its components include the skin, mucous membranes, phagocytes, natural killer (NK) cells, cytokines, and complement factors. The latter two elements control and mediate immune function and help activate T- and B-lymphocytes, key parts of the acquired immune system. In contrast to the innate system, the acquired system protects the body against specific infectious agents during both initial and subsequent attacks.1

The body’s first line of defense consists of skin and mucous membranes, which can be impaired by temperature, wind, sun, humidity, and trauma. Many upper respiratory pathogens are airborne and affected by airflow patterns, mechanical barriers, and ciliary action in the respiratory tract.1

During exercise, the sportsperson switches from nasal to mouth breathing, and this can increase deposition of harmful articles in the lower respiratory tract. It also causes increased cooling and drying of the respiratory mucosa, which slows ciliary movement and increases mucous viscosity.2

NK cells express spontaneous cytolytic activity against cells infected with viruses.1 NK cell counts increase 150–300% immediately after high-intensity exercise lasting less than 1 hour. Within 30 minutes of the end of such high-intensity exercise, however, NK cell counts fall below pre-exercise levels.3 NK cell activity increases by ...

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.