Gaps stay gaps.
Missing data is shown as missing, nothing is filled in across a gap, and an older reading shows its time.
For Polar Loop and iPhone
Find your even keel.
Keely reads your Polar Loop and tells you how recovered you are, how hard to go, and how you’re handling the day. Every number is explained, and nothing is made up.
Coming soonon the App Store
Need a Polar Loop?
A day with Keely
Last night · 23:24–07:00
Your night, as a story.
Keely reads the night your Loop recorded: sleep stages with heart rate, HRV and breathing on one timeline, time asleep against your need, and when to turn the lights out tonight.
How Sleep works23:24Now: In bed
23:2401:0003:0005:0007:00
7 h 20 masleep
88%of your need
47 bpmlowest heart rate
When you wake · 07:00
Every number, explained.
Keely scores last night against your own 30-night normal. HRV and resting heart rate carry most of the weight, with sleep, breathing rate and skin temperature alongside.
Tap the score to see what moved it: each reading against its usual range, and what it was measured from.
- Primed 67–100
- Balanced 34–66
- Restore 0–33
What moved itvs your 30-day normal
All 4 overnight readings inside your usual range
HRV70 ms
Helping · usual 58–72Clean beats for 3 h 10 m
Resting heart rate49 bpm
Helping · usual 48–54From clean beats
Sleep7 h 20 m
Holding back · 88% of your needWorn all night
Breathing14.1 rpm
Normal · usual 13.6–14.6From your beats
Skin temperature+0.1 °C
Normal · usual up to +0.3 °COnly warmer counts
Through the day
A target that moves with you.
Load counts every minute by its heart-rate zone. It’s linear and has no ceiling: twice the work is twice the Load.
Each morning brings a target range set by your Recovery and your last four weeks. Balance says how this week compares with the weeks before, and active minutes count toward WHO’s 150–300 a week.
How Load works05:00Now: Everyday
06:0009:0012:0015:0018:0021:00
0LoadBuilding
0Today 132–179no ceiling
BalanceThis week vs the 3 before
0.98Steady
This week 145 a day · your usual 148 · 7 of 7 days measured
Active minutesThis week
185Within 150–300
Moderate 1 h 35 m, vigorous 45 m counted twice.
Right now
Stress as it happens.
With your Loop connected and Keely open, stress updates live from your heart rate and beat-to-beat variability, scored from 0 to 100 against your own calm.
While you move, it reads your heart rate alone, on the same scale, so the day has one line. Moments show when it stood out, day and night.
- Calm 0–25
- Mild 26–50
- Elevated 51–75
- High 76–100
Live from your Loop58 bpm
23Calm
From heart rate alone while you move · An older reading always shows its time.
Week after week
The shape of your weeks.
Regularity is the chance you’re asleep or awake at the same times 24 hours apart, over the last 14 days. The daily rhythm shows when you’re most active and when you’re quietest. Your HRV week sits against your own band, not anyone else’s.
RegularityLast 14 days
88Regular
12:0018:0000:0006:0012:00
Asleep or awake at the same times 24 hours apart, 94% of the time. Hours your Loop wasn’t worn are left out, never counted as awake.
Daily rhythmLast 14 days
Most active09:00–19:00
Quietest01:00–06:00
HRV this weekvs your band
59msUsual for you
48 msYour band 54–6370 ms
From your walks and runs · every Monday
Your fitness, in years.
Keely puts the pace of the walks and runs your watch or apps save to Apple Health against your Loop’s heart rate, on steady, level stretches, for your VO2 max with its likely range. Never from resting guesswork, and never your routes.
Keely Age is the age whose average mortality risk matches fitness like yours. It moves only when your fitness really does, and it says what moved it.
How Fitness works How Keely Age worksVO2 max13 runs, 6 weeks
45ml/kg/min
Likely 40 to 50 · good for your age
Keely AgeEvery Monday
32years
Likely 29 to 34 · a year younger since April
In the app
Calm screens, made to be read half awake.
Calm by design
Quiet until it matters.
Keely is made to be read half awake in a dark bedroom. It says what it knows, shows what it doesn’t, and keeps its voice down.
Every formula, in the openEvery score shows its work.
Each number keeps its inputs, so you can always see what moved it and by how much.
Cool is normal. Warm asks.
Color means good or bad, not up or down, and it always comes with a word or an arrow.
No ceiling on effort.
Load is linear: twice the work is twice the Load. No gauge gets harder to fill the higher you go.
And more
It learns you.
Keely adapts quietly to your own sleep, your own calm and the workouts you name, and it keeps the context that explains your numbers.
- The journalTag a late meal, a drink or a trip, in a tap or your own words, and see how each moves your next morning’s HRV and resting heart rate.
- Every number’s historyTap HRV, resting heart rate, Recovery, stress or Load for its week, month, six months or year, against your own normal.
- Your cycle, if you track itRecovery compares each night with nights of the same phase, said looking back. Your answers stay on your iPhone.
- LandmarksYour first Recovery, 100 days with your Loop, your 25th run: marked once, quietly, and yours to share as a card.
- Your assistantConnect Claude or ChatGPT to ask about your numbers, and your journal if you share it.
- Apple HealthKeely can save your sleep, workouts, resting heart rate and breathing rate to Health.
Private by default
Your heartbeat stays on your iPhone.
Keely computes every score on your phone. Only your account, profile, band and daily summaries are backed up, so a new iPhone can pick up where you left off.
- Every heartbeat, day and night
- On this iPhoneYour raw heart data stays on your phone.
- Your cycle and journal
- On this iPhoneYour journal goes only to assistants you let read it.
- Daily scores and summaries
- Your accountBacked up for a new iPhone.
- Which screens you open
- AnonymousNever health data. Off in Settings.
- Ads and data sales
- NoneNo ads, and your data is never sold.
What you need
Your Loop, understood.
Pair your Polar Loop once. Keely syncs, reads your night and learns your normal over your first few nights, and the scores firm up as it does.
- A Polar LoopKeely talks to it directly over Bluetooth, instead of the Polar Flow app. Already on Flow? Keely walks you through the move.
- An iPhoneWith iOS 26 or later.
We may earn a commission when you buy through this link. As an Amazon Associate, Metrica Fit earns from qualifying purchases. Keely is an independent app and isn’t affiliated with or endorsed by Polar Electro.
A keel is the spine under a boat. It carries the ballast that pulls the hull upright after every gust.
Keely does that job for a body. It reads what the day put on you and what the night gave back, and helps you stay level.
Coming soonon the App Store
Need a Polar Loop?