The influence of paced breathing exercises on the autonomic response to stress

Time-frequency analysis of heart rate variability is a noninvasive method to measure rapid changes in the functioning of the sympathetic and parasympathetic nervous systems. In the course of measuring the autonomic reaction to stress and relaxation, it was found that paced breathing at frequencies different from the subject's natural breathing frequency can cause a stress reaction to the pacing as measured by time frequency analysis of heart rate variability. It was also found that changes in skin temperature correlated to the changes in stress level during the paced breathing protocol.