Journal
What your resting heart rate is actually telling you (and what it isn't)
A useful, slow-moving signal about how your body is coping. Read it against your own normal, not someone else's.
Your resting heart rate is how fast your heart beats when you're properly at rest. Most watches estimate it from the quietest parts of your night. It's one of the simplest numbers your watch records, and one of the most useful, as long as you read it the right way.
Your number is personal
Resting heart rates vary a lot from person to person. Fitness plays a part, but so do age, genetics and body size, and even where the watch sits on your wrist. Comparing your number with a friend's, or with a chart online, tells you very little. Comparing it with your own recent weeks tells you much more.
That's why Tempest never shows you a "good" or "bad" resting heart rate. It shows yours against your usual range, worked out from your own previous weeks.
Why it moves
When your resting heart rate sits above your usual range for a few days, it's often a sign your body is working harder to recover. Everyday reasons include:
- a run of short or broken nights
- a hard training block, or a big event
- alcohol, especially late in the evening
- a stressful spell at work or at home
- heat, travel or a change of time zone
- coming down with a cold
A gentle drift downwards over months, alongside regular exercise, often goes with improving fitness. Single days bounce around; the trend over weeks is what matters.
The context is the useful part
On its own, "your resting heart rate is up" isn't much use. It becomes useful when you can put it next to your week. Did it rise the morning after a late, hard session? During a run of short nights? While work was full-on? Most people find two or three things that reliably move their number, and once you know yours, the number becomes a reminder rather than a worry.
Three habits that make it more useful
- Wear your watch the same way every night. A loose strap or a different wrist can shift the reading.
- Look at weeks, not days. One high morning is noise. Several in a row is worth noticing.
- Note what's going on. Travel, a busy week, a cold in the house: it's much easier to make sense of the data later if you've noted it.
What it isn't telling you
A watch reading isn't a medical test. It can't tell you whether your heart is healthy, and a reading outside your usual range on its own isn't a reason to worry. Watches also get it wrong: a loose strap, a cold wrist or a restless night can all nudge the number.
If a change comes with chest pain, breathlessness, a racing or irregular heartbeat, or dizziness, don't wait for the trend: call 999 for chest pain, otherwise NHS 111.
Tempest describes your own data; it doesn't diagnose or treat anything. If you're worried about your health, speak to your GP or call NHS 111. In an emergency, call 999.