The aim of this paper is to describe the structure, production and function of secretory immunoglobulin A (sIgA) as well as changes of its concentration caused by exercise of various intensity and duration. Immunoglobulin A is the main class of antibodies present in the body secreted fluids such as saliva, tears or mucus from the intestines. It is generally recognized that IgA, due to its dominance in the immune system of mucous membranes, is the first line of defence against harmful environmental factors. The secretion and composition of saliva depends on the activity of the sympathetic and parasympathetic nervous systems. Physical activity, stimulating the autonomous nervous system, may reduce the amount of saliva and/or inhibit its secretion. The relationship between physical activity and the suppression of the immune system is not fully understood, but it is known that moderate intensity exercise can improve immune defences, while extreme effort can reduce them by creating an increased risk of upper respiratory tract inflammation (URTI). In athletes, the lowest risk of upper tract infection was connected with the case of moderate intensity exercise. It is now believed that the relationship between exercise volume and the risk of URTI has the shape of the letter “J”. This means that both too little and too much physical activity may increase the risk of upper respiratory tract infection. Training optimization and correct balance between exercise and rest periods may reduce the risk of adverse changes in the immune system and decrease the frequency of URTI.

SummaryStudy aim: the aim of the present study was to investigate the effect of 12-week training on saliva immunoendocrine response in collegiate male and female wrestlers. Material and methods: the control group was composed of men and women of the same age, not engaged in any sports activity except for physical education classes at the university. The examined athletes participated in a 12-week training program, which consisted of two sub-phases (preparatory period and competitive period). Saliva samples were collected at three time points: at the beginning (the first point), after six weeks of the preparatory period (the second point, which was the start of the competitive period) and after six weeks of the competitive period (the third point). Immunoglobulin A and cortisol concentration, and α-amylase activity were measured in saliva by respective ELISA kits. Immunoglobulin A was expressed as relative to total protein concentration (sIgA/total protein). Results: at the third time point, the sIgA/total protein ratio was significantly lower in female compared to male athletes. α-Amylase activity was lower in all examined athletes at all three time points compared to respective control groups. Conclusions: hormonal and mucosal antimicrobial system response can provide helpful information of body adaptive processes to physical strain as well as indicators of magnitude of training-induced stress.