Return to Play After Infectious Disease

Acute illnesses are of significant concern for the health and performance of athletes. Sports medicine physicians face the challenge of promoting sufficient recovery and responding to the demands of the coaches and athletes. This chapter presents the evidence behind the risk factors for acute illness in athletes, the negative consequences of sports participation during illness and the recommendations for safe sports participation. Risk factors for infection and illness may be intrinsic (e.g. postexercise suppression of the immune system, recent acute illness, female gender) and extrinsic (e.g. training load, nutrition, resting periods). Fever during illness contributes to systemic symptoms such as headache and myalgia but also to dehydration, muscle breakdown and reduction in cardiometabolic function. The consequences of exercise during illnesses may be aggravation of illness, loss of muscle strength and endurance, cardiac complications, transmission of infection to others, neurological dysfunctions including coordination problems, rhabdomyolysis and in the worst case sudden death. Recommendations for safe return to sport include clearance of infection allowing full recovery and thereafter gradual progress of exercise volume combined with monitoring of remaining symptoms of illness. Different actions can be taken to prevent acquiring, aggravating and spreading of infections by the athlete (e.g. hygiene, physical contact, covering of the body, sharing of equipment, nutrition), the coaches (e.g. individualised plan of training, competition, nutrition, recovery and recovery measures) and the physicians (monitor and implement illness prevention, identify and arrange for high-risk athletes, educate athletes and staff).