Resting heart rate is one of the simplest health metrics available, requiring no special equipment beyond a basic wearable or even a manual pulse check — and it's genuinely informative over time.
A downward trend usually reflects improving fitness
As cardiovascular fitness improves, resting heart rate typically trends lower over months of consistent training — a useful, low-effort way to see progress beyond the scale or the mirror.
A sudden spike can be a useful early warning
An unusually elevated resting heart rate on a given day can be an early sign of overtraining, illness, or poor recovery — worth noticing rather than training through automatically.