Oura reports that heart rate variability (HRV) measures the variation in heartbeat timing, reflecting stress levels and recovery. Higher HRV indicates well-being, while lower HRV signals stress.

Once upon a time, I was involved in an abortive attempt to measure the variation of the fundamental constants. Thanks to that experience, I’ve always had an interest in these measurements, so a new ...

1. Despite widespread focus on interspecific variation in trait-based ecology, there is growing evidence that intraspecific trait variability can play a fundamental role in plant community responses ...

Heart rate variability offers a closer look at how your heart behaves from one beat to the next. While heart rate measures the average number of beats per minute, heart rate variability bases a ...