The role of resonance frequency in slow-paced breathing: Systematic review

A healthy heart does not beat like a metronome because it shows characteristics of complex non-linear oscillations and mathematical chaos, together with the existence of resonance in the cardiorespiratory system (Shaffer et al., 2014). On one swing, the inhalation causes an increase of the heart rate, while the opposite effect is during exhaling, thus having variability properties in the inter-beat intervals. By utilizing this effect of respiratory sinus arrhythmia, resonance frequency (RF) gives insight into the respiratory rate at which this resonance is amplified in the heart rate, blood pressure, and respiration systems (Shaffer & Meehan, 2020). The aim of this systematic review was to examine the effects of resonance frequency in Slow-Paced Breathing (SPB) studies, as well as the relation between RF and anthropological measures of gender, height, and age.