Effects Of An Incremental Exhaustive Exercise On Core Body Temperature And Serum Stress Neurotransmitters

Objective: The purposes of this study were to examine the impacts of an incremental exhaustiveexercise on core body temperature and serum stress neurotransmitters in a normal temperatureenvironment (room temperature:23±1℃, relative humidity:40±2%), and to evaluate the relationsamong the core body temperature and heart rate, blood lactate, serum stress neurotransmitters bymonitoring the core body temperature and heart rate continuously during exercise. The resultscan provide the theoretical basis for controlling core body temperature during the training, andto improve performance with scientific guides of hyperthermia.Methods: Ten male endurance athletes majored in physical education volunteered in ShenyangSport University participate study. The participants performed an incremental exercise toexhaustion on a cycle ergometer. The workload was initially set to100W and increased by20Wevery10min at a pedaling cadence of60rmp. In the course of the experiment, core bodytemperatures and heart rates were measured continuously. Blood were collected at pre-exercise(PRE), exercise20min（E20）, exercise40min（E40）, post-exercise(POE), and post-exercise30min(POE30). Serum dopamine and noradrenaline were determined.Results:1. At POE, the exercise period to exhaustion was63.3±6.6min, the maximum powerwas218±11W, the weight lost1.11±0.23kg, the maximum heart rate was186.3±10.0b/min, theheart rate increased92.4±11.8b/min. The heart rate gradually rose with time during theincremental exercise. At POE30，the heart rate recovered to PRE（P>0.05）.2. The core body temperature appeared at slowly rose during the incremental exercise.The maximum temperature（38.7±0.4℃）arrived post-exercise2.3±2.0min, then the core bodytemperature were slowly decreased and did not recover to PRE at POE30（P<0.05）.3. Compared with before exercise， there were no significant differences in dopamine andnoradrenaline（P>0.05）.Conclusions：1. The core body temperatures are gradually increased with time and exercisehyperthermia is caused during incremental exhaustive exercise in a normal temperatureenvironment.2. Serum dopamine and noradrenaline are not altered during the incremental exhaustive exercisein a normal temperature environment.