Could regular practice of volleyball modulate salivary secretory immunity in children? Cross-sectional and longitudinal studies

Introduction The aim of these studies was to evaluate the effects of regular volleyball training on salivary SIgA and alpha-amylase in female children and adolescents. Material and method In the cross-sectional study, 115 female children (12.6±2.2 years) participating in a Volleyball training program were classified as beginners, intermediate, and competitive level. The children were evaluated regarding caries index, body mass index (BMI), cardiorespiratory fitness, and countermovement jump. In the longitudinal study: 54 girls (intermediate and competitive groups) trained for 8 weeks and were re-evaluated at weeks 4 and 8. Results The SIgA secretion rate and alpha-amylase activity did not present correlations with training category, age, caries index, or training status. A weak positive correlation was detected between IgA secretion rate and BMI (r=0.20, p<0.05). After 8 weeks of training, VO2max (p<0.005) and jump height (p<0.005) improved in the competitive girls. No differences were observed in salivary secretion rate, SIgA concentration and secretion rate, or alpha-amylase activity at weeks 4 and 8. Conclusion We concluded that despite improving physical fitness, 8-weeks of recreational volleyball training are not able to improve salivary SIgA secretion or alter alpha-amylase activity in female children and adolescents.