Custom Smartphone Application to Guide Locomotor-Respiratory Coupling in the Field Using Step-Adaptive Breathing Sounds

Summary

Locomotor-respiratory coupling (LRC) is potentially advantageous for runners but may be difficult to perform. We introduce a custom solution implemented on a smartphone to individualize and guide runners toward LRC.

Abstract

While running is amongst the most popular activities for competition and leisure, an estimated 20-40% of runners may suffer from respiratory limitations. Some of these runners may benefit from breathing techniques to improve performance or alleviate respiratory discomfort. One such technique is locomotor-respiratory coupling (LRC), a frequency and phase synchronization of breath to step. Studies have demonstrated that LRC may benefit ventilatory efficiency via "step-driven flows," and some experts have argued it could be used for pacing exercise or increasing positive emotional states. Nevertheless, it may be difficult to perform without coaching or guidance. Here we propose RunRhythm, a custom smartphone application to deliver step-synchronized sound guidance for LRC. This concept builds on previous evidence that sound guidance can be effective and integrates features to maximize adherence and individualization. Preliminary results show that this application is a promising and efficacious method suitable for research on LRC in field exercise. Recommendations for use and further development are discussed to further develop this concept for the benefit of a wider population.

Introduction

Running is perhaps the most widely popular form of exercise in part due to its accessibility and range of physical and mental health benefits^1,2. Nonetheless, many aspiring runners struggle to start or maintain running habits. This could be due to breathing difficulties, which affect an estimated 20-40% of runners^3,4,5. Reducing exercise-induced breathlessness is theoretically possible with the use of specific breathing techniques, but the exact methods, risks, and benefits of doing so are unclear. While improving fit....

Protocol

This study was granted ethical approval by the Ethics Committee of the University of Salzburg (reference number: GZ 13/2021), and the participants gave their informed consent.

1. Getting started with RunRhythm

1. Have the participants fill out a prequestionnaire to include demographic information, as well as running, sports, and breathing experience.
2. Download the application to a functioning smartphone running Android 8.0 or later.
   ​NOTE: Closed.......

Discussion

This methodology presents one of the first evidence-based, field-ready digital tools for instructing LRC to runners. Early results suggest that it is effective not only in quickly learning and adhering to LRC but can also be taught over time and retained. While LRC may emerge naturally with increased running experience, novices are less likely to perform it³⁷. Coincidentally, they are especially likely to experience barriers to participation that include poor fitness and respiratory limitations

Materials

Name	Company	Catalog Number	Comments
Android smartphone	Samsung or Google		Minimum Android 8.0 required for application functionality
FMOD engine	Firelight Technologies Pty Ltd		Sound engine
Hexoskin smart shirt	Carré Technologies		Wearable sensor shirt
RunRhythm application for Android	adidas GmbH and abios GmbH