Effect of pre-season training camp on oral immune functions in elite collegiate volleyball players

In various sports, high-intensity training reduces the oral immune function of the player. The effect of volleyball training camp on salivary immune function is unclear. This study aimed to investigate the effect of pre-season training on salivary immune function in elite collegiate volleyball players. Twenty-one elite collegiate volleyball players (mean age: 19.6 ± 1.1 years, mean height: 185.2 ± 7.8 cm) participated in this observational study. Saliva samples were taken on Day-1 (First day) and Day-11 (Final day) during pre-season training camp. Fatigue was measured using a VAS (visual analog scale) every day during the training camp period. Oral immune function was assessed in terms of secretory immunoglobulin A (s-SIgA) secretion rate and nitric oxide (s-NO) secretion rate. The s-NO secretion rate showed no significant change from Day-1 (0.69 ± 0.49 µmol/min) to Day-11 (0.56 ± 0.33 µmol/min). How-ever, the s-SIgA secretion rate on Day-11 (28 ± 16 µg/min) was significantly lower (P < 0.05) than that on Day-1 (35 ± 18 µg/min). Changes in fatigue scale scores positively correlated with changes in s-NO secretion rate ( r s = .591, P < 0.01), but not with changes in s-SIgA secretion rate ( r s = .411, P = 0.06). In this study, the concentration of s-NO stored frozen was determined, but the effect of the storage method on s-NO should be investigated in future studies. In conclu-sion, pre-season volleyball training camp may affect oral immune function as in other sports.