Relaxation Effects of Personalized Breathing Exercises for Healthy College Students

Stress plays a major role in the etiology and pathogenesis of anxiety and depression. Relaxation therapies, such as breathing exercises, can reduce stress and increase relaxation. This study has two aims. First, it aims to personalize and optimize breathing protocols. Second, it aims to tailor breathing protocols to subgroups based on prediction models of expected efficacy. Three different breathing protocols, varying solely in their instructed breathing frequency with 40 percent (A), 60 percent (B), and 80 percent (C) of the interindividual spontaneous breathing frequency, are tested in a randomized, counterbalanced crossover trial. Other parameters, such as breathing quality (i.e., nasal and diaphragmatic), rhythm (i.e., prolonged exhalation without instructed pauses) and depth (i.e., increased depth due to slower breathing frequency) as well as contextual factors (e.g., posture, video-based instructions, type of pacer, etc.) are invariant between protocols. First, this study hypothesizes a difference in the relaxation response between breathing protocols A, B, and C. This study looks at the relaxation response from three different angles (1) self-report, (2) autonomic arousal, and (3) central nervous system arousal. Second, this study explores prediction models of expected efficacy based on the interindividual variance in characteristics (i.e., depressive, anxious and stress symptoms as well as expertise in relaxation therapies) and biomarkers (e.g., heart rate variability, peripheral temperature, skin conductance, etc.). Prediction models can tailor breathing protocols to subgroups to increase expected efficacy.