Comparison of BRS Estimates during Mild Dynamical Exercise and Recovery

Ten estimates of baroreflex sensitivity (BRS) were compared during progressive graded exercise: they were computed from sequence method, spectral and cross-spectral analysis methods, and parametric model-based methods. Results showed baroreflex control of heart rate (HR) changes as a function of the intensity of exercise, as well as the resetting phenomenon. Sequence, spectral and cross-spectral methods generally provided higher estimates than parametric model- based ones. This bias was particularly evident during exercise, and in the high frequency (HF) respiratory band. Results may suggest that the interaction of respiration and baroreflex function play an important in the cardiovascular adaptation from rest to exercise and from exercise to the recovery period.