Heart-rate variability, or HRV, has become a buzzword in the age of smartwatches and fitness trackers—but what does it actually reveal about your health? Unlike resting heart rate, a higher HRV signals a flexible, resilient nervous system that can smoothly shift between stress and recovery. When illness, anxiety, or overtraining strike, that variability drops, offering a window into the body’s total stress load. In this episode, we explore the science behind HRV, why context matters more than a single score, and how wearable data can be transformed into smarter decisions about training, rest, and overall well-being.

https://www.economist.com/science-and-technology/2026/01/16/the-most-useful-indicator-of-your-overall-health