Evaluation of visual and vibratory guidance for resonance frequency breathing

INTRODUCTION: Resonance frequency breathing is a non-pharmacological self-regulation technique used in heart rate variability biofeedback and complementary health practices. However, optimal guidance methods for home-based and self-directed practice remain unclear. METHODS: We conducted a randomized, open-label crossover trial in 72 healthy volunteers. Participants performed 4min of paced breathing at a predicted resonance rate under three conditions (visual guidance, vibratory guidance, no guidance), with 3-min rest periods before and after each session. The primary outcome was the change in short-term heart rate variability. The secondary outcome was the percentage of time judged as "resonant" based on blinded waveform assessment. RESULTS: Both visual and vibratory guidance were associated with significantly greater increases in heart rate variability during and after paced breathing compared with no guidance (P < 0.001). No significant difference was observed between visual and vibratory guidance (P = 0.360). The proportion of time judged as resonant was significantly higher with both guidance methods than with no guidance (P < 0.001), without differences between guidance modalities (P = 0.110). CONCLUSION: Visual and vibratory guidance may facilitate adherence to paced breathing at a predicted resonance rate and increase short-term heart rate variability under these conditions. TRIAL REGISTRATION: UMIN000052363. Registered 1 October 2023.