Heart rate variability change induced by the mental stress: the effect of accumulated fatigue

Abstract

Evidence is shown that accumulated fatigue greatly affects statistical properties of the heart rate fluctuations. Comparison of heart rate variabilities before and after an exhausting physical and mental task was made for six volunteer male subjects. Significant changes in mean heart rate, variances and spectral characteristics were found showing the importance of considering the background physical and mental condition in the characterization of the heart rate.