Resonance frequency is not always stable over time and could be related to the inter-beat interval


Author: Lluis Capdevila1,2, Eva Parrado3,4, Juan Ramos-Castro5, Rafael Zapata-Lamana6, Jaume F Lalanza3,7

Affiliation: <sup>1</sup> Departament of Basic Psychology, Universitat Autònoma de Barcelona (UAB), Bellaterra, Barcelona, Spain. lluis.capdevila@uab.cat.

<sup>2</sup> Sport Research Institute, Universitat Autònoma de Barcelona (UAB), Bellaterra, Barcelona, Spain. lluis.capdevila@uab.cat.

<sup>3</sup> Departament of Basic Psychology, Universitat Autònoma de Barcelona (UAB), Bellaterra, Barcelona, Spain.

<sup>4</sup> Sport Research Institute, Universitat Autònoma de Barcelona (UAB), Bellaterra, Barcelona, Spain.

<sup>5</sup> Department of Electronic Engineering, Biomedical and Electronic Instrumentation Group, Universitat Politècnica de Catalunya, Barcelona, Spain.

<sup>6</sup> Escuela de Educación, Universidad de Concepción, Los Ángeles, Chile.

<sup>7</sup> Department of Psychology, UiT The Arctic University of Norway, Tromsø, Norway.
Conference/Journal: Sci Rep
Date published: 2021 Apr 16
Other:
 Volume ID: 11   ,  Issue ID: 1   ,  Pages: 8400   ,  Special Notes: doi: 10.1038/s41598-021-87867-8.   ,  Word Count: 178  
    Heart Rate Variability Biofeedback (HRVB) is based on breathing at an optimal rate (or resonance frequency, RF) corresponding to the respiratory sinus arrhythmia (RSA). Our aim is to check whether the RF is a stable factor and analyse the HRV parameters individually per each breathing rate, comparing it with free slow breathing. A sample of 21 participants were trained in a test-retest HRVB protocol. The results indicated that RF changed between Test and Retest sessions in 66.7% of participants. This instability could be related to the average of interbeat interval (IBI). HRV time domain parameters (SDNN and RMSSD) were significantly higher for RF than for other breathing rates, including 6 breath/min and free slow breathing. Free slow breathing showed a lower heart rate averages than RF and other slow breathing rates. Overall, our study suggests the relevance of assessing RF individually and before each HRVB session, because the maximum cardiovascular benefits in terms of increasing HRV were found only at RF. Thus, breathing at the individualized and momentary frequency of resonance increases cardiac variability.





PMID: 33863966 DOI: 10.1038/s41598-021-87867-8