Salivary Immuno Factors, Cortisol and Testosterone Responses in Athletes of a Competitive 5,000 m Race

The exercise-stress model can be a model of temporary immunosuppression that occurs after
severe physical and psychological stress. It also allows for the study of interactions between the endocrine
and the immune systems. This study examined changes in salivary hormonal and immune factors
in athletes in response to physical and psychological stress in a 5,000 m running competition. Eighteen
endurance-trained runners (9 males and 9 females) participated in this study. All participants completed
a competitive 5,000 m race. Saliva samples were collected 10 min before (PRE) and 10 min after
(POST) the competition. Saliva was analyzed for α-amylase activity, concentrations of salivary immunoglobulin
A (SIgA), lactoferrin, cortisol, testosterone and total protein. Although the concentrations of
salivary TP, SIgA, lactoferrin, cortisol and α-amylase activity were significantly increased immediately
after a competitive 5,000 m race, the secretion rates of these factors were not significantly altered in both
male and female groups. Additionally, basal levels of SIgA and α-amylase activity were significantly
higher in female runners than in male runners. This gender difference still existed after the race. The
secretion rates of testosterone decreased significantly after the race in the male, but not in the female group.
Moreover, testosterone-to-cortisol (T/C) ratios were significantly lower post-competition compared to
pre-competition in both male and female athletes. The T/C ratio had been used as a performance index
for athletes. Whether there are correlations between these changes of their physiological characteristics
and better running performance need further investigations.