Resting Heart Rate (RHR)

Resting heart rate (RHR) is the number of times your heart beats per minute when you're awake but completely at rest. Healthy adults typically fall between 60 and 100 bpm; trained endurance athletes can be in the 40s.

RHR is one of the simplest and most useful biomarkers a wearable can give you. It changes slowly over time as your fitness improves or declines, and it spikes acutely when you're sick, hungover, sleep-deprived, or stressed.

Most consumer wearables measure your lowest nightly heart rate as a proxy for true resting heart rate. This is more reliable than spot measurements taken during the day because nighttime HR is much less affected by random daily variation.

Watch your RHR trend over weeks, not days. A 3–5 bpm increase over a week often shows up before you consciously notice you're getting sick or burning out.