The efficacy of interventions aimed at reducing the incidence of Upper Respiratory Tract Infections (URTI) in athletes following the performance of strenuous, intense, prolonged exercise – a systematic review

  • Ethan J. Berndt
  • Candice J. Christie


Endurance athletes appear to be at a higher risk of contracting upper respiratory tract infections (URTI) during periods of intense training and following major competition. Immunoglobulin A (IgA) has been found to provide major resistance to many pathogenic micro-organisms and therefore salivary IgA is currently considered the best indicator of mucosal immunity. This review aims to assess the status of the literature on the efficacy of interventions to reduce the incidence of URTI in athletes following the performance of strenuous, intense prolonged exercise. Medium evidence indicates that Pelargonium sidoides supplementation or a high carbohydrate diet significantly increased the concentration of salivary IgA, while chronic glutamine supplementation did not significantly increase salivary IgA concentration. Medium evidence also showed that the consumption of a high carbohydrate diet had a significant positive effect on the immunosuppressive stress hormone cortisol, while limited evidence showed that a high protein diet resulted in a reduced number of self-reported symptoms of URTI.


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