Plasticity of heart rate modulation of young adults during paced breathing with different frequencies

: The effect of paced breathing 10, 9, 8, 7, 6, 5, 4 times per minute with 160 and 90 s duration on the plasticity of slow modulations of heart rate was studied on 29 participants aged 21, both men and women. It was shown that the power spectrum of RR-intervals have dominant harmonics both in high- and low-frequency domains, peaking at 0.08-0.06 Hz for 160 s segments. Low-frequency peaks of the spectrum were growing in power linearly as a result of the graded slowing down of breathing rate. Frequency-dependent modulations of RR-intervals for a wide range of breathing frequencies confirm a substantial cardio-respiratory plasticity underlying cognitive and somatic processing.