Resting heart rate (RHR)

What it is

Resting heart rate is the number of beats per minute when you’re awake but completely at rest, or in wearable terms, the lowest stable heart rate during quiet periods or sleep. Endurance training often lowers it over months.

Why it matters for training decisions

Day to day, the useful signal is change from your own normal, not the absolute number. A resting heart rate that sits above your usual range for a couple of days, especially alongside lower HRV, can reflect accumulated fatigue, the start of an illness, dehydration, heat, alcohol, travel or poor sleep.

Researchers note that heart rate measures work best when you account for normal measurement noise and for context, such as the training phase you’re in, rather than reacting to every small change. Resting heart rate also can’t tell you everything about fatigue, which is why it works best next to HRV, how sessions feel and how you’re performing.

How wearables measure it, and the limits

Different devices define “resting” differently. Apple Watch estimates it from background readings taken while you’re still. WHOOP measures it during your last period of slow-wave sleep. A morning reading taken lying in bed is different again. So numbers from different devices or methods can’t be compared, but each is reasonably consistent with itself.

Caffeine, a late meal, a hot bedroom or a restless night can all lift the number without saying anything about your training.

How P247 uses it

Resting heart rate is one of the inputs to P247’s daily recovery score, where it’s rated against a fixed reference value rather than your own baseline. The weekly report also watches HRV and resting heart rate together when deciding whether recovery kept up with training.

This glossary is general information to help you understand your training data. It isn't medical advice, diagnosis or treatment. For injury, illness, medication, blood test results or any health concern, speak to a qualified health professional.

← Back to the glossary