Heart rate variability, trait anxiety, and perceived stress among physically fit men and women

Background: It is unclear from prior reports whether the relationships betw een self-ratings of anxiety or emotional stress and parasympathetic nervous system components of heart rate variability are independent of personality and cardiorespiratory fitness. We examined those relationships in a clinic al setting prior to a standardized exercise test. Methods and results: Hear t rate variability (HRV) was measured during 5 min of supine rest among 92 healthy men (N = 52) and women (N = 40) who had above-average cardiorespira tory fitness as indicated by peak oxygen uptake measured during grade-incre mented treadmill exercise. HRV datasets were decomposed into low-frequency (LF; 0.05-0.15 Hz) and high-frequency (HF; 0.15-0.5 Hz) components using sp ectral analysis. Self-ratings of trait anxiety and perceived emotional stre ss during the past week were also assessed. Conclusions: There was an inver se relationship between perceived emotional stress during the past week and the normalized HF component of HRV (P = 0.038). This indicates a lower car diac vagal component of HRV among men and women who perceived more stress. That relationship was independent of age, gender, trait anxiety, and cardio respiratory fitness. It was also independent of heart rate; mean arterial b lood pressure; and respiration rate, factors which can influence HRV and mi ght be elevated among people reporting anxiety and perceived stress. We con clude that vagal modulation of heart period appears to be sensitive to the recent experience of persistent emotional stress, regardless of a person's level of physical fitness and disposition toward experiencing anxiety. (C) 2000 Elsevier Science B.V. All rights reserved.