Heart Rate Variability Training

HRV biofeedback (HRVB), or resonance-frequency breathing, is one of the better-studied self-regulation techniques. A 2017 meta-analysis (24 RCTs, 484 participants) found a large reduction in self-reported stress and anxiety versus control (Hedges' g ≈ 0.83). A broad 2020 systematic review of 58 RCTs found small-to-moderate benefits across many domains, largest for anxiety, depression, anger and athletic/artistic performance. A 2025 meta-analysis of remote/app-based HRVB (18 studies, 1,352 participants) found a medium effect for reducing depressive symptoms (g ≈ -0.41) and for raising HRV (g ≈ 0.44), while the pooled effect on stress was not statistically significant. In cardiovascular-disease patients, a 2026 meta-analysis (13 RCTs, 965 participants) reported modest reductions in systolic (~-3.1 mmHg) and diastolic (~-3.2 mmHg) blood pressure alongside improved SDNN, though effects on parasympathetic (HF) indices and mood were inconclusive and most trials carried risk-of-bias concerns. Overall the evidence is encouraging for stress, anxiety and autonomic balance, with meaningful heterogeneity across protocols. HRVB is a low-risk complementary practice for self-regulation and recovery, not a treatment for any disease.

Evidence Scale