Exercise effects on mucosal immunity

The present review examines the effects of exercise on mucosal immunity in recreational and elite athletes and the role of mucosal immunity in respira tory illness. Habitual exercise at an intense level can cause suppression o f mucosal immune parameters, while moderate exercise may have positive effe cts. Saliva is the most commonly used secretion for measurement of secretor y antibodies in the assessment of mucosal immune status. Salivary IgA and I gM concentrations decline immediately after a bout of intense exercise, but usually recover within 24 h. Training at an intense level over many years can result in a chronic suppression of salivary immunoglobulin levels. The degree of immune suppression and the recovery rates after exercise are asso ciated with the intensity of exercise and the duration or volume of the tra ining. Low levels of salivary IgM and IgA, particularly the IgA1 subclass, are associated with an increased risk of respiratory illness in athletes. M onitoring mucosal immune parameters during critical periods of training pro vides an assessment of the upper respiratory tract illness risk status of a n individual athlete. The mechanisms underlying the mucosal immune suppress ion are unknown.