Exercise and upper respiratory tract infection

Abstract

The relationship between physical and psychologic stress, immune function, and upper respiratory tract infection (URTI) is reviewed in this article. There are relatively few studies that have explored this relationship. Of seven studies currently published, five are epidemiologic in design (two prospective and three retrospective), and only two used a randomized, controlled experimental design. In general, these studies support the concept that, although risk of URTI may decrease below that of a sedentary individual when engaging in moderate exercise training, risk may be elevated during periods of excessive amounts of exercise. Risk of URTI in athletes appears to be especially high during the 1‐ or 2‐week period following marathon‐type race events. Among runners varying widely in training habit, the risk for URTI is slightly elevated for those runners with the highest training mileage only when several confounding factors are controlled for. This interpretation is consistent with experimental evidence from both human and animal studies.

Key words:

• upper respiratory tract infection
• exercise
• stress
• immune system