Changes of Salivary IgA of athletes after a single bout of exercise in cold, warm and natural environments

Introduction: Exercise and environmental stressors cause alteration in different
components of the immune and hormonal systems. Therefore, the purpose of this study was
to explore the changes of serum cortisol and salivary IgA of athletes after a single bout of
exercise cold, warm and natural environments.
Methods: Ten young male athletes who ran on a treadmill for 1 hour at %60 VO2max in
environments of natural (22±1°c, 50±5 RH), cold (3±1°c, 50±2 RH) and warm
(35±1°c, 50±5RH). Blood and Saliva samples were collected to measure cortisol and
SIgA before, after exercise and 2 hours after recovery. In addition, during exercise body
temperature, athletes’ consumption water, Plasma Volume Changes, perceived exertion
(borg scale) were measured. In order to analyze the data, Repeated Measure and Bonferroni
tests at the significant level of P<0.05 were utilized.
Results: The cortisol concentration increased significantly after exercise, in three
environments (P<0.0001). This increased values were significant in warm in comparison
with cold (P=0.04) and natural (P=0.031) environments. SIgA concentrations, in three
environments, did not have significant changes after exercise. However, these values
reduced significantly after exercise in cold environment compare to natural (P=0.021) and
hot environment compare to natural (P=0.035).
Conclusion: Exercise in the three environments causes increase serum cortisol as well as
stimulating the Hypothalamic-Pituitary-Adrenal (HPA) axis. But, exercise had no effect on
the levels of SIgA. However, regard to a significant reductions of these values in cold and
warm environments than natural environment after exercise, is possible a risk of respiratory
tract infection in cold and warm environments.