Beats per minute at complete rest. A simple, reliable indicator of cardiovascular fitness and autonomic health — and one of the most accurately measured wearable metrics.
Resting heart rate (RHR) is the number of times the heart beats per minute when the body is at complete rest — typically measured first thing in the morning before rising. It reflects the baseline demand placed on the heart and the efficiency of cardiac output.
Lower resting heart rate generally indicates a more efficient cardiovascular system: a well-trained heart pumps more blood per beat (higher stroke volume), requiring fewer beats to meet the body's resting metabolic demands.
| Category | RHR (bpm) | Notes |
|---|---|---|
| Athlete | 40–60 | Common in endurance-trained individuals |
| Normal | 60–100 | AHA-defined normal adult range |
| Elevated | 100–110 | Warrants monitoring if sustained |
| Tachycardia | >100 | Medical term; multiple causes |
| Bradycardia | <60 | Normal in athletes; may need assessment otherwise |
Source: American Heart Association. Target Heart Rate and Estimated Maximum Heart Rate. 2021.
| Age | Males — Median | Females — Median | Athlete Range |
|---|---|---|---|
| 18–25 | 68 | 72 | 40–55 |
| 26–35 | 70 | 73 | 42–57 |
| 36–45 | 71 | 73 | 44–59 |
| 46–55 | 72 | 74 | 45–60 |
| 56–65 | 73 | 74 | 46–62 |
| 65+ | 73 | 75 | 48–63 |
Source: Jensen MT et al. Resting heart rate in adults and cardiovascular disease risk. Int J Cardiol. 2012.
Resting heart rate is among the most accurately measured wearable metrics. Optical PPG at rest achieves high agreement with ECG (mean absolute error typically <2 bpm during sleep). Wrist-based devices are slightly less accurate than ring or chest-based devices, but errors at rest are clinically insignificant for trending purposes.