Different Characteristics of Heart Rate Variability in Mental and Physical Fatigue States / 航天医学与医学工程

ABSTRACT

Objective Using heart rate(HR) and heart rate variability(HRV) as stress level indices,to find out the changes of stress level in mental fatigue and physical fatigue,respectively.Methods The changes of HR and HRV during reading task and written calculation task were studied in mental fatigue,and the change of HR during exhausting physical exercise was analyzed in physical fatigue.Results Subjects showed high stress level as heavy mental load was imposed on at the beginning of the experiment.Decreased HR and increased HRV caused by physiological inhibitory protection,indicating an increased mental fatigue level,showed that mental fatigue level was opposite to mental stress level under heavy mental workload.The phenomenon that HR increased along with the physical fatigue level increasing,proved that physical fatigue degree was often consistent with physical stress level,which revealed the compensative adjustment.Conclusion The significant difference of autonomic nervous system(ANS) activity between mental fatigue and physical fatigue,may be explained by the difference between mental stress and physical stress of mechanism,mainly born organ and workload intensity.