Resting heart rate: what your pulse at rest tells you

When your pulse does not settle, even at rest

Resting heart rate is the number of heartbeats per minute when you are relaxed and not moving. Apple describes the value as an estimate of your lowest heart rate during periods of rest¹.

For groups, a higher resting heart rate goes with a higher risk of death: in an analysis of 46 studies, the risk of death from any cause was on average 9 % higher for every 10 beats per minute more². That is a statistical link across many people and years. It does not tell you what a single number on your watch means for you.

Normal is what is normal for you

There is no normal value that fits everyone. How high a resting heart rate is differs from person to person. What matters more is where yours usually is and whether it moves away from that.

This is also how research on smartwatch data works: in a study of nearly 5,300 participants, many of those who later became infected showed early spikes in resting heart rate, measured against their own baseline³. Single nights vary by a beat or two without meaning anything. Only a deviation over several nights says something.

What affects your resting heart rate

• ↓lowers: regular endurance training, over weeks⁴
• ↑raises: an infection^{3, 5}
• ↑raises: the second half of the cycle⁶
• ↑raises: a higher body weight⁸

Endurance training has the clearest effect: in an analysis of 191 studies in healthy people, all kinds of sport lowered resting heart rate, but only endurance training and yoga did so significantly⁴. That takes weeks, not single sessions.

An acute infection can raise resting heart rate⁵. In people with confirmed COVID-19, heart rate and respiration rate were typically elevated and HRV was lowered⁹.

Over the cycle, pulse during sleep is higher after ovulation: in a study of 91 women it was on average 3.8 beats per minute higher in the mid-luteal phase than during the period⁶. That is not a sign of poor recovery but a normal rhythm¹⁰.

Alcohol in the evening disturbs the relaxation of the cardiovascular system during the first hours of sleep, even in small amounts and more strongly the more was drunk⁷. In a study using smartphone pulse measurements, a higher body mass index went with a higher pulse and older age with a lower one⁸.

How your watch measures resting heart rate

Watches and rings measure the pulse optically at the wrist or finger. How a resting heart rate is derived from it is up to each manufacturer. Apple Health stores it as its own value (restingHeartRate): the watch estimates it from pulse readings taken in quiet moments during the day and replaces earlier estimates of the day with better ones as more data arrives¹.

What Salvor does with it

Salvor compares each night’s pulse with your own range of the last 28 days and scores only the deviation from yourself. It learns that range over the first 14 nights. A raised resting heart rate counts as strain, an unusually low one is not treated as a warning sign.

The nocturnal pulse makes up 30 % of the body signals, next to HRV (40 %), breathing rate and temperature. If you log your period in Apple Health, Salvor compares a night in the second half of the cycle with matching nights rather than with the average of both halves.

When to see a doctor

A raised resting heart rate on its own is not a diagnosis. In the second half of the cycle, for example, it is often a few beats higher without anything being wrong. If you have symptoms such as a racing heart, dizziness, shortness of breath, chest pain or a fever that does not go away, talk to a doctor, whatever a watch shows. In an emergency, call 112.