In this episode, we review seven new studies published between September 19 and September 25, 2025. Together, they highlight the many ways HRV intersects with brain activity, breathing practices, cardiac recovery, exercise environments, emergency medicine, environmental stressors, and new multimodal measurement approaches. We’ll explore: How brain networks and cognitive load shape HRV readings. Why slow breathing alone is powerful, and what feedback really adds. The Benefits of Yoga Nidra for Patients Recovering from Coronary Artery Bypass Surgery. How walking in natural environments provides a stronger autonomic boost than indoor or urban exercise. Real-world HRV findings in emergency medicine and why lab results don’t always translate. How pollution, heat, and noise suppress vagal tone. New frontiers in dynamic and multimodal HRV metrics. As always, I’ll connect the research to practical, client-ready strategies you can use right away. This podcast is sponsored by Optimal HRV. Learn more at optimalhrv.com. References  Behavioural Brain Research – Neural and cognitive influences on autonomic function. https://doi.org/10.1016/j.bbr.2025.115811 Psychophysiology – Comparing HRV biofeedback and slow-paced breathing. https://doi.org/10.1111/psyp.70156 Cureus – Impact of Yoga Nidra on heart rate variability in coronary artery disease patients undergoing coronary artery bypass grafting. https://www.cureus.com/articles/402202-impact-of-yoga-nidra-on-heart-rate-variability-in-coronary-artery-disease-patients-undergoing-coronary-artery-bypass-grafting-a-comparative-study Psychology of Sport and Exercise – Green exercise randomized controlled trial. https://doi.org/10.1016/j....