Effects of Tai Chi and Qigong on Heart Rate Variability: A Systematic Review and Meta-Analysis

Background: Intervention studies examining meditative movement (MM) often demonstrate benefits on physiological and psychological health. A potential mechanism associated with these outcomes is heart rate variability (HRV), an important neurophysiological biomarker of optimal and resilient health and functioning. Objective: We aimed to synthesize existing literature on the effects of two related forms of MM, Tai Chi (TC) and Qigong (QG) on HRV parameters in adult populations. Methods: Following PRISMA guidelines and Cochrane Collaboration recommendations, four databases (MEDLINE, Google Scholar, Academic Search Premier, and PubMed) were searched for articles (through December 15, 2023) that included TC and/or movement-based QG intervention versus any control condition (active or inactive) and reported at least one HRV outcome. Two reviewers independently completed study selection, data extraction, and risk-of-bias assessment. Results: We identified 148 for potential inclusion. After removing 61 duplicates, 87 full-text reviews yielded 23 articles, and 16 qualified for meta-analysis based on common HRV outcomes. Meta-analyses indicated a significant overall effect of TC/QG interventions on high-frequency power and standard deviation of the beat-to-beat intervals (SDNN), two critical HRV parameters, compared with control conditions: for HF power, standardized mean difference (SMD) = 0.29, P = 0.003, 95% Confidence interval (CI) [0.10, 0.48]; heterogeneity: I-2 = 46%, chi(2) (8) = 14.89, P = 0.06; and for SDNN: SMD = 0.83, P = 0.02, 95% CI [0.16, 1.51]; heterogeneity: I-2 = 90%, chi(2) (7) = 71.62, P < 0.001. Other HRV parameters did not demonstrate significant changes upon meta-analyses, but overall effect sizes showed a trend toward the expected direction. Conclusion: Based on the strength of the evidence, we conclude TC/QG interventions may shift HRV parameters toward improved health status and resilience. In addition, we offer suggestions to improve the design and measurement of future TC/QG research interventions exploring HRV.