Salivary IgA Responses to Prolonged Intensive Exercise following Caffeine Ingestion

• Autores: Nicolette C. Bishop, Gary J. Walker, Gabriella A. Scalon
• Localización: Medicine & Science in Sports & exercise: Official Journal of the American College of Sports Medicine, ISSN 0195-9131, Vol. 38, Nº. 3, 2006, págs. 513-519
• Idioma: inglés
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• Resumen

  • Purpose: Prolonged, intensive exercise is associated with a reduction in concentration and secretion of salivary IgA (s-IgA). Saliva composition and secretion are under autonomic nervous system control, and caffeine ingestion, a widespread practice among athletes for its ergogenic properties, is associated with increased sympathetic nervous system activation. Therefore, this study investigated the influence of caffeine ingestion on s-IgA responses to prolonged, intensive exercise.

    Methods: In a randomized crossover design, 11 endurance-trained males cycled for 90 min at 70% [latin capital V with dot above]O2peak on two occasions, having ingested 6 mg[middle dot]kg-1 body mass of caffeine (CAF) or placebo (PLA) 1 h before exercise. Whole, unstimulated saliva samples were collected before treatment (baseline), preexercise, after 45 min of exercise (midexercise), immediately postexercise, and 1 h postexercise. Venous blood samples were collected from a subset of six of these subjects at baseline, preexercise, postexercise, and 1 h postexercise.

    Results: An initial pilot study found that caffeine ingestion had no effect on s-IgA concentration, secretion rate, or saliva flow rate at rest. Serum caffeine concentration was higher on CAF than PLA at preexercise, postexercise, and 1 h postexercise (P < 0.001). Plasma epinephrine concentration was higher on CAF than PLA at pre- and postexercise (P < 0.05). s-IgA concentration was higher on CAF than PLA at mid- and postexercise (P < 0.01), and s-IgA secretion rate was higher on CAF than PLA at midexercise only (P < 0.02). Caffeine ingestion did not affect saliva flow rate. Saliva [alpha]-amylase activity and secretion rate were higher on CAF than PLA (main effect for trial, P < 0.05).

    Conclusions: These findings suggest that caffeine ingestion before intensive exercise is associated with elevated s-IgA responses during exercise, which may be related to increases in sympathetic activation.