Changes in saliva composition during different training phases in professional football players.

OBJECTIVE: This study investigated changes in salivary biomarkers collected by oral rinsing during different phases of a standard professional football training, and how these changes correlated with perceived training intensity. METHODS: This study included 28 professional football players. Saliva was collected by means of oral rinse with water. It was collected at three time-points during a single training session: before training, after warming-up, and after outdoor training. Players were asked to self-report the intensity of the training after each time-point on a scale from 1 to 10. The following biomarkers were measured: protein, carbohydrate and immunoglobulin-A (IgA) concentrations, and enzymatic activity of α-amylase, lactoperoxidase and lysozyme. RESULTS: Protein concentration increased during training (p < 0.001). α-Amylase activity/protein ratio (p < 0.001) increased while the IgA/protein ratio(p < 0.001) and carbohydrates/protein ratio (p = 0.001) significantly decreased. No association was found between the self-perceived intensity of training and changes in the biomarkers. CONCLUSIONS: This study shows that saliva composition changes in response to a regular football training session. These changes did not correlate with self-perceived intensity of training.