Same Breath, Different Device: Comparing VR and Smartphone Biofeedback Breathing Training

Slow breathing holds promise in strengthening mental resilience and reducing acute stress. Prior work presented distinct prototypes of smartphone and VR mobile biofeedback breathing trainings (MBBTs) but lacked direct comparisons. This study aimed to evaluate whether a VR MBBT offers advantages over smartphone MBBT in perceived (relaxation) effectiveness and intention to use, while maintaining non-inferiority in perceived breathing detection accuracy. A within-subject laboratory study with 67 participants was conducted. No evidence was found that the VR MBBT was perceived as more effective. The breathing detection algorithm, originally optimized for smartphones, was perceived as non-inferior in VR MBBT, indicating potential for cross-platform scalability. We found no evidence that intention to use was higher for VR, suggesting that practical considerations such as accessibility and cost may outweigh technology-based preferences. Although these findings are promising, future research must assess their applicability in the real world and ensure accessibility to VR for equitable use.