“HRV is the single greatest non-invasive proxy that we have for measuring the adaptations of the nervous system.” — Dr. Jay Wiles What is HRV (and why should you care)? Heart Rate Variability (HRV) is the variation in time between each heartbeat, measured in milliseconds. It might sound small—but it’s incredibly powerful. HRV reflects how well your autonomic nervous system is balancing two key systems: Sympathetic (fight or flight) → mobilizing energy Parasympathetic (rest an
