Effects of a 4-week Vinyasa Yoga Intervention on Sleep and Cardiovascular Health in Adults with Insomnia Symptoms: A Pilot Randomized Controlled Trial

STUDY OBJECTIVES Vinyasa yoga (VY) yields moderate-intensity physical activity that may improve sleep and cardiovascular health (CVH). However, evidence is scarce regarding the effects of VY on CVH. This study examined the effects of a 4-week VY intervention on sleep and CVH in adults with insomnia symptoms. METHODS 33 insufficiently active adults (84.8% female; 78.8% White; 34.9±10.6 y; 28.9 kg/m2) with insomnia symptoms (Insomnia Severity Index [ISI]≥10) were randomized to a 4-week VY intervention (n=17) or non-active control (CON; n=16). VY participants practiced 3x/week following pre-recorded 60-minute videos and CON maintained their current lifestyle. Resting daytime blood pressure (BP), heart rate (HR), and HR variability (HRV) were obtained at baseline and post-intervention. Sleep was measured using the ISI, actigraphy, and a sleep diary. One night during sleep assessment, participants wore a chest HR monitor to assess HRV; primary HRV outcome was root mean square of successive differences. Analyses used linear mixed models and Cohen’s d effect sizes. RESULTS Changes in ISI, actigraphy- and diary-assessed sleep from baseline to post-intervention did not differ between groups (each p>0.06). Changes in nocturnal HRV and daytime resting BP and HRV were not significant (each p≥0.30). Resting HR decreased for VY (72.41±2.92 to 69.50±2.60 bpm) and increased for CON (70.47±2.54 to 72.93±2.60 bpm) (p=0.047). Additionally, among highly adherent participants, VY reduced ISI scores more than CON (p=0.002). CONCLUSION VY improves insomnia symptoms among those who practice regularly. It does not appear to improve nocturnal cardiovascular physiology, and shows modest benefits on daytime cardiac parasympathetic activity. Clinical Trial Registration Registry: ClinicalTrials.gov; Name: Yoga for Insomnia (YOGi) Study; URL: https://clinicaltrials.gov/study/NCT05723211; Registration ID: NCT0572321; Date of Registration: 2/01/2023