More devices
Garmin first, then Apple Watch and others.
How it works
Your watch measures. Tempest understands.
A watch app gives you numbers and a score. Tempest connects them to your life, finds what actually affects you, helps you test it, remembers what worked, and has a real person behind it.
Follow Sam through their first 12 weeks. Sam is an example, not a real member.
1 Week 1 · Tell it about you
It starts with a conversation
ComingChoosing your tone and how often to check in works in testing now
Sam talks about their goals, a normal week and when they train. Tempest asks; your watch never does.
TempestGetting to know youWeek 1Tempest AIWhat would make the next few months feel like a win?SamMore energy in the afternoons. And I'm running a 10k in the spring.Tempest AINice. What does a normal week look like: work, training, anything that knocks you off course?SamLong days Tuesday and Wednesday. I usually train after work, so it's often late.Tempest AIGot it. I'll keep that in mind while I learn your normal.Illustration of how Tempest will work. Sam is an example. 2 Weeks 1 to 4 · It learns your normal
First it listens
In testing now
A number only means something compared with how you usually are, so Tempest waits until it knows. We'd rather show a gap than fill it with a guess.
Week 1
"Still getting to know you."
No normal yet
Week 2
"Starting to see your pattern."
No normal yet
Week 4 · 28 nights
"Now I know your normal."
Sleep6h 30m–7h 32mResting HR52–56 bpmHRV42–50 msFrom your watch
From you
Illustration of how Tempest will work. Sam is an example. 3 Week 6 · Same night, two readings
Your watch gives Sam a number. Tempest gives Sam a reason, and something to try.
In testing now
The numbers come from fixed rules; the AI puts them into words. If you mention a warning sign, such as chest pain, coaching stops and you're pointed to the right help.
Your watch says
Three numbers and a status. And then?
Tempest says
Tempest AI
Your HRV has been below your normal most of this week, the same stretch you marked as busy at work. You also tend to sleep about 40 minutes less after evening sessions, and three of this week's finished late.
Want to try finishing before 7pm for a week? I'll compare your sleep.
- Your normal 41–49 ms
- You told me busy at work
- Your history 6 of 8 evening sessions
- Compared with you Not an average person: your own normal.
- Connected to your life What you've told it, and what's going on.
- Something to try One small change, then it checks whether it worked.
Illustration of how Tempest will work. Sam is an example. 4 Weeks 1 to 6 · It finds what affects you
Sam sleeps less after evening sessions
In testing now
Found in Sam's own last six weeks, not a general rule. Travel and the busy spell at work are left out so they don't skew it.
−40minutes of sleep after evening sessionsNights after a session finishing after 7pm6h 33m
Other nights7h 15m
Each dot is one night. The line is the average. Tempest only mentions a pattern when it holds up: here, 6 of 8 evening sessions.
Illustration of how Tempest will work. Sam is an example. 5 Week 8 · Try one small thing
One change, for one week
In testing now
What to do, for how long, and how Sam will know. Sam waits for a normal week first, so there's a fair week to compare with.
An experiment for you · 7 days
Finish your runs and workouts before 7pm
- Why
- You sleep less after evening sessions
- How you'll know
- Your sleep that week, against the week before
Illustration of how Tempest will work. Sam is an example. 6 Weeks 9 and 10 · Find out if it worked
An honest answer, either way
In testing now
Tempest compares Sam's week with the one before and says plainly what changed, including when nothing did.
Experiment 1 · finished
+25minutes of sleep a night, on averageDuring "Finish your runs and workouts before 7pm", your sleep averaged 7h 24m on 7 recorded days, against 6h 58m on 7 days before. That's a change in the direction you were after.
Experiment 2 · finished
No clear change
During "No caffeine after 2pm", your sleep averaged 7h 21m on 7 recorded days, against 7h 15m on 7 days before: no clear change.
Sam dropped it. That's useful to know too.
Illustration of how Tempest will work. Sam is an example. 7 All along · It remembers
In Sam's words, and Sam's to change
In testing now
Each thing Tempest learns shows where it came from. Sam can edit, delete, download it all, or turn memory off.
What I remember about you
- Running a 10k in the springYou told me, week 1
- Long days on Tuesdays and WednesdaysYou told me, week 1
- Finishing training before 7pm helps my sleepYour experiment, week 8
- Prefers short messagesYou chose this
Illustration of how Tempest will work. Sam is an example. 8 Every week, on Coached · A real person behind it
A coach reads it first
In testing now
Sam's coach sees the AI's draft and the same evidence, then adds their own judgement. Nothing is sent automatically.
AlexYour coach (example)Week 9Alex, coachNice work on the earlier sessions, Sam: your sleep was up the week you tried it.
With the 10k six weeks out, let's keep Tuesdays easy, since that's your long day. How are your legs feeling?
Drafted with AI, reviewed by Alex (example coach)SamLegs are good! Tuesdays easy makes sense.Illustration of how Tempest will work. Sam is an example. 9 Week 12 · Looking back
What Sam learned
ComingWeekly reviews work in testing now
What Sam kept, what made no difference, and what's next, all against Sam's own starting point.
Kept
Finishing training before 7pm on weeknights
Didn't change much
No caffeine after 2pm: no clear change in sleep, so Sam dropped it
In Sam's words
"I know why my bad weeks happen, and what to try."
Next
An easier week before the 10k
Illustration of how Tempest will work. Sam is an example.
Where it's going
Blood tests and a clinician
Later, as an optional premium layer.
Always describing
Tempest will keep describing your data, never diagnosing.
The principles behind it
Rules calculate, AI explains
Your baseline, trends and patterns are worked out by fixed, tested rules. The AI only turns those results into plain English, and its words are checked before you see them.
Describe, don't diagnose
Tempest tells you what your data shows compared with your own normal. It never tells you what's wrong with you, and it points you to your GP or NHS 111 if something worries you.
You control what's remembered
Everything Tempest remembers about you is on one page, where you can change or delete it, download it, or switch memory off.
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.
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