The Effect Of Incremental Test On Lactic Acid, Testosterone, Cortisol Of Saliva And Relationship With Blood On Male College Students In Shenyang Sport University

Objective: The objective of the study were to observe the lactic acid, testosterone, cortisol ofsaliva and blood during incremental test and to further explore the effect of exercise on lacticacid, testosterone, cortisol of saliva and relationship with blood.Methods:17active male college students in Shenyang Sport University were recruited assubjects (Age:20.76±1.60ys,height:177.41±4.95cm,weight:72.51±72.51kg,body fat percentage:12.05%±5.64%,the training period:4.7±4.7ys).About an hour of incremental test to exhaustionwas conducted in the laboratory. Saliva and blood were collected at pre-exercise (PRE),exercise20min(E20),40min(E40),post-exercise(POE) and post-exercise30min(POE30).Physiologicalindicators such as lactic acid, testosterone, cortisol of saliva and blood were determined at PREand POE. Anthropometry including body height, body weight, and body composition weremeasured.Results:1.There were no significant difference on salivary lactic acid concentration and secretionrate between E20, E40and PRE; salivary lactic acid concentration and secretion rate increasedsignificantly at POE compared with PRE; there was no significant difference on salivary lacticacid concentration and secretion rate at POE30compared with PRE. Salivary lactic acidincreases significantly after40min exercise and recovers to the pre-exercise after30min rest.2.Lactic acid concentration of blood and serum increased significantly at E20,E40,POEcompared with PRE; lactic acid concentration of blood and serum increased significantly atE40,POE compared with E20;lactic acid concentration of blood and serum increasedsignificantly at POE compared with E40;lactic acid concentration of blood and serum increasedsignificantly at POE30compared with PRE. Blood lactic acid changes significantly duringincremental test and does not recover after30min rest. Blood lactic acid is more sensitive thansalivary lactic acid.3.Concentration and secretion rate of salivary lactic acid were significant correlated withlactic acid concentration of blood and serum during exercise.4.There were no significant difference on testosterone concentrations, cortisolconcentration, T/C of saliva and serum during exercise. 5.There was a decreasing trend on salivary secretion rate of testosterone and cortisol, thoseparameters at POE were significantly lower than PRE, and recovered to pre-exercise after30min rest. Incremental test causes secretion rate of saliva testosterone and saliva cortisoldecrease, which recovers to the pre-exercise after30min rest.6.There were no correlation on testosterone, cortisol,T/C between saliva and serum.7.There were significantly negative correlation on concentration of serum betweentestosterone and cortisol at PRE(R=-0.652,P=0.008).There were significantly negativecorrelation during exercise(R=-0.545,P=0.000).8.There were no correlation on concentration of saliva between testosterone and cortisol atPRE(R=-0.23,P=0.409).There were significantly negative correlation during exercise(R=-0.482,P=0.000).9.There were significantly positive correlation on secretion rate of saliva betweentestosterone and cortisol(R=0.966，P=0.000)(R=0.945，P=0.000)(R=0.937，P=0.000)(R=0.899，P=0.000)(R=0.916，P=0.000). There were significantly positive correlation during exercise.(R=0.941，P=0.000).Conclusions：1.There are significant correlation between salivary lactic acid and blood lactic acid. Thatsalivary lactic acid used to monitor exercise is suggested.2.There are no significant correlation on testosterone, cortisol, T/C between saliva andserum; that saliva may be candidate to blood to monitor training need further study.