Effects of cardiorespiratory fitness on changes in secretory immunoglobulin A following a maximal exercise test

BACKGROUND: This study investigated if a maximal exercise test affects changes in secretory immunoglobulin A (SIgA). Additionally, this study examined if changes in SIgA were different between higher- and lower-fit females.METHODS: Nineteen females (age 19.8±2.6) participated in this study. Unstimulated saliva was collected before and five minutes after a V̇O2max test. An Enzyme-Linked Immunosorbent Assay (ELISA) was used to determine absolute SIgA concentrations. SIgA secretion rate (SR) and salivary flow rate (SFR) were also determined. Using the American College of Sports Medicine Fitness Classifications, the higher fitness group (HF) were those who had a V̇O2max value considered "good" or above and the lower fitness (LF) group had a V̇O2max value of "fair" or below.RESULTS: Following exercise, the whole sample demonstrated significant increases in SIgA concentration (P<0.001) and SR (P<0.001). The HF group (m=49.3 mL∙kg-1∙min-1) was significantly different than the LF group (m=37.3 mL∙kg-1∙min-1) (P<0.001). There was no interaction between fitness group and time (pre and post) for SFR, concentration, or SR (P>0.05).CONCLUSIONS: Maximal exercise testing resulted in increased SIgA concentration and SR in both groups. Differences in fitness level did not appear to affect the concentration, SR or SFR of SIgA following maximal exercise.