Meditation, HRV, and Two Different Routes to Regulation
MBSR may improve how people use cardiac signals during emotion regulation, while slow breathing raises HRV during practice. What the evidence supports.
HIIT Can Delay HRV Recovery. Does Training Time Matter?
HIIT delays HRV recovery more than moderate exercise. A small trial suggests training time may affect heart-rate recovery—but not yet in healthy HIIT users.
Fish Oil and HRV: Why a Slower Pulse Isn’t Better Vagal Tone
Does fish oil improve HRV? Four small RCTs found no consistent placebo-controlled effect, though DHA-rich fish oil can slow resting heart rate in adults.
Does Pre-Workout Caffeine Lower HRV After Exercise?
Pre-workout caffeine does not consistently reduce post-exercise HRV in pooled trials, but strength training and individual responses complicate the answer.
Vagus Nerve Stimulation and Opioid Withdrawal Pain
A tiny tcVNS pilot linked lower opioid withdrawal pain with HRV changes. The biomarker signal is plausible, but it cannot prove treatment or mechanism.