Still Point turns a heart-rate chest strap (a Polar H10 or any standard Bluetooth chest strap) into a calm morning check-in. A short reading each day tracks your heart rate variability (HRV) against your own usual range, an optional standing test adds how your heart rate responds to getting up, and a breathing guide helps you slow down. It is free, needs no account, and nothing leaves your device.

Wellness use only

Still Point is for general wellness, training and relaxation. It has not been tested, cleared or approved by any medical regulator. Do not use it to diagnose, rule out or monitor any illness, or to make decisions about medicines or treatment. Words such as "usual range" describe how a reading compares with your own earlier readings. They are not medical findings.

Slow breathing can make some people light-headed. If that happens, stop and breathe normally. If you are pregnant or have a heart, lung or blood-pressure condition, check with your doctor before slow-breathing practice. Do the standing test only where you can sit down straight away.

What you need

• A Polar H10 or any standard Bluetooth chest strap that sends beat-to-beat intervals: for example a Garmin HRM-Dual or HRM-Pro, Wahoo TICKR, Coospo, Magene or Decathlon strap (a Polar H9 also works). Watches that broadcast heart rate usually don't send the beat-to-beat data HRV needs; Still Point tells you if a device doesn't.
• Google Chrome or Chromium on Android. On a computer, Chrome or Edge. iPhone, iPad, Safari and Firefox cannot connect to the strap.
• The app opened from its https address: stillpoint.anonacondacodelab.com

No strap to hand? Choose any reading and, where it asks you to connect your strap, tap try a simulated strap. It produces made-up heart beats so you can explore the app. At the end of a reading, tap Discard so made-up readings stay out of your history.

Choosing what to do

The HRV tab (the first tab) asks what you'd like to do:

• Morning reading: the daily check-in that builds your baseline.
• Morning reading + standing test: the same reading, then you stand up for 2 minutes (see below).
• Spot check: a reading at any other time. It is saved and charted but never changes your baseline, because HRV naturally runs lower later in the day.
• Breathe: the breathing guide.

The morning reading

1. Moisten the electrodes, put the strap on and close other apps connected to it.
2. On the HRV tab, tap Connect strap and choose your strap from the list.
3. Choose Morning reading, then your position and reading length. Two minutes is plenty; use the same choices every day. The app remembers them.
4. Tap Begin. The first 15 seconds let you settle; if you're already still and ready, tap Skip settling. Then the reading runs. Stay still and breathe normally.

While it runs you see a live heart-rate trace of the last minute, beat by beat, and your heart rate, your HRV (RMSSD over the last minute), your breathing rate and the signal quality. In the trace, the area above your average is shaded teal where your heart speeds up (usually as you breathe in) and lavender where it slows (as you breathe out), so each breath shows as a gentle wave: taller waves mean higher HRV. Beats left out as glitches appear as small grey rings off the line. In the standing test, a dashed line marks the moment you stood up. HRV and breathing appear after about half a minute and update every couple of seconds. Don't try to steer them: just breathe normally.

1. When it finishes, look over the result and tap Save reading, or Discard if something went wrong (you moved, talked, or it wasn't your usual routine).

Get the most from it: read at the same time each morning, soon after waking, after the bathroom and before coffee, food or exercise, in the same position. Consistency matters far more than the exact routine you choose.

Your result

• HRV score: lnRMSSD on a 0–100 scale (lnRMSSD × 100 / 6.5). Several apps use a similar scale, but the numbers are not interchangeable between apps.
• lnRMSSD and RMSSD: the standard short-reading HRV measure, from the strap's own beat-to-beat intervals.
• Heart rate: average over the reading.
• Breathing: about how many breaths a minute you took (3 to 30). It is estimated from your heart rhythm, which rises and falls slightly with each breath, so it is approximate and may be missing if your rhythm didn't show a clear pattern.
• Signal: beats that differ by more than 20 % from their neighbours (a missed or extra beat, or a strap glitch) are left out. If more than 10 % are left out, the reading is marked noisy and does not count towards your baseline. During a reading, the Signal box shows the quality of the last few dozen beats (good, fair or poor).
• Strap: the strap's model is saved with each reading (just the model, such as "Polar H10", not its serial number).

Your reading, beat by beat

Every result shows the whole reading as a heart-rate trace with the same teal and lavender shading (the faded strip at the start is the settle period). A standing test gets its own trace with the moment you stood up and your peak heart rate marked.

Next to it, the beat-to-beat pattern plots each beat against the next (a Poincaré plot). A wide, round cloud means a lot of variation from beat to beat (higher HRV); a narrow cloud along the diagonal means less. Grey rings are beats that were left out.

Breathing and HRV

How you breathe moves HRV: slow, deep breathing raises it and faster breathing lowers it. So breathe the way you usually do during readings, whether that's normal or naturally slow. If a morning reading was breathed much faster or slower than your usual (by more than about half again), the result says so, so you don't mistake a change in breathing for a change in you.

What this means

Under every result, a short What this means section explains in everyday words what HRV is, what today's reading suggests and what, if anything, to do about it. Once your baseline is ready it also gives some context: where your usual value sits compared with published averages for healthy adults (roughly 20 to 75 ms RMSSD lying down, falling with age).

The app deliberately doesn't grade HRV as favourable, normal, borderline or outside normal range the way Lead One ECG grades ECG measurements. Healthy people of the same age can differ two- or threefold in HRV, mostly because of genetics, so a population grade would worry people with naturally low HRV for nothing and reassure people with high HRV even when their own trend is sliding. Comparing you with your own usual range is what the research supports.

Your baseline

HRV varies a lot between people, so a single number means little. After 7 earlier mornings in the same position, each reading is compared with your own usual range:

• Usual range is your 60-day average ± half a standard deviation of your daily values.
• Your 7-day average is compared with it, because day-to-day values bounce around.
• In your usual range: nothing stands out.
• Lower than usual: often follows hard training, short or poor sleep, alcohol, illness, travel or stress. An easier day and an early night are sensible.
• Higher than usual: usually good recovery; occasionally, with unusual tiredness after very heavy training, a sign of being run down.

Only the first good reading of each day counts, and each position has its own baseline.

Changing straps. Chest straps time each beat slightly differently. If your baseline mixes readings from different strap models, Trends says so, because a step in your trend around a switch may be partly the strap. For the fairest comparison, use the same strap each morning.

Training guidance

Once your baseline is ready, morning results include a suggestion for today's training, based on the published HRV-guided training approach (Kiviniemi 2007, Plews 2013):

• Go as planned, or Good day for a harder session when you are above your usual range and today isn't low.
• Keep it easy: your 7-day average is below your usual range, or today is clearly lower than your usual.
• Rest or very light: today is well below your usual and either your week is low or your resting heart rate is 5 or more beats up.

It's a suggestion: how you feel counts too. Switch it off in Settings → Options if you don't train.

Tags (optional)

Under each result, + Add tags lets you note anything that may have affected the reading: slept badly or well, alcohol last night, hard training or a rest day yesterday, sore muscles, feeling ill, stressed, a late or heavy meal, caffeine before the reading, travel or jet lag, period. You can also enter a sleep score (0–100, as shown by a Garmin, Oura, Fitbit or similar), hours slept and any sleep aids you took the night before (herbal or other, such as magnesium or chamomile tea; separate several with commas). Aids you've used before appear as buttons, so they're one tap next time. Tags are entirely optional; you can add or change them later by opening the reading.

Something about skipped beats

If several of your recent readings (3 of the last 7) had beats left out even though the signal was good, the result suggests recording with Lead One ECG, our ECG app, which shows the actual heart trace from the same strap so you can see whether the odd beats were the strap or real early beats. Occasional early or skipped beats are common and usually harmless; if you have symptoms such as palpitations, dizziness or chest discomfort, see a doctor.

The standing test

Choose Morning reading + standing test (from lying or sitting). It uses your morning position and length, so the reading part joins your baseline as usual. After the reading, a chime asks you to stand up calmly and stay standing, still, for 2 minutes. You'll see:

• Peak after standing: your highest heart rate in the first 30 seconds, and how far it rose.
• Standing, last minute: where your heart rate settled, compared with lying or sitting.
• 30:15 ratio: the longest beat interval around the 30th beat after standing divided by the shortest around the 15th. It reflects how quickly your heart rate comes back down after the initial jump.

Compare these with your own earlier tests; Trends charts them over time.

Breathe

Choose a rhythm and a length:

• Longer out (40 % in, 60 % out, the more relaxing choice) or Even, with a pace from 3 to 7 breaths a minute in half steps.
• Box 4-4-4-4: in 4 s, hold 4 s, out 4 s, hold 4 s.
• 4-7-8: in 4 s, hold 7 s, out 8 s.
• Custom: set your own breath in, hold, breath out and hold, from 1 to 20 seconds (holds from 0) in half-second steps.

Follow the circle: it grows as you breathe in and shrinks as you breathe out, with a soft chime at each change if you like. Breathe gently through your nose into your belly. Don't force the breath; if you feel short of air, choose a faster pace.

With the strap connected you'll see your heart rate rise as you breathe in and fall as you breathe out, and the size of that swing per breath.

Find your resonance pace

At one particular pace, usually between 4.5 and 6.5 breaths a minute, the swing is largest. The test guides you through 6.5, 6, 5.5, 5 and 4.5 breaths a minute for two minutes each and picks the pace with the biggest swing. Tap Use … as my pace to make it your default; it is marked with a dot among the pace buttons. Retest every month or two.

Open session

No guide and no counting: sit or lie comfortably, breathe naturally and let your mind settle. Choose open-ended or a length from 5 to 30 minutes (a soft chime marks the end). With the strap on, your heart rate and HRV are shown quietly, and the summary compares your first and last two minutes: as you settle, heart rate usually drifts down and HRV up.

Trends and history

Trends shows the last 60 days: HRV score with your 7-day average and usual range, resting heart rate, standing-test results, spot checks and your breathing and open-session minutes. Tap any item in the history to open it.

This week and your weekly recap

This week on Trends sums up the current week (Monday to Sunday): morning readings, average HRV score and resting heart rate compared with the week before, standing tests, breathing and open-session minutes, and your most-used tag. At the start of each week, the HRV tab shows Your week, the same summary for the week just finished, until you tap Got it.

What affects you

Once you've tagged some mornings, this card shows how each tag relates to your HRV, for example "Alcohol last night: HRV about 12 % lower than on other mornings". Each sleep aid is compared the same way as a tag. A tag needs at least 3 mornings with it and 5 without; sleep score and hours slept need 8 mornings and compare your lower half with your upper half. Only differences of 5 % or more are listed. These are patterns in your own readings, not proof of cause.

What your trend shows

Once your baseline is ready, the top of Trends comments on the last few weeks in plain language. A green dot is reassuring, an orange dot is worth noticing, and a grey dot is about how the readings are taken. It looks at:

• Direction: whether your 7-day average is below or above your usual range, and for how many days, or slowly drifting over two weeks.
• Day-to-day variation: readings that jump around more than usual are often an early sign of strain, before the average itself drops.
• Heart rate and HRV together: resting heart rate up while HRV is down is a clearer sign of strain than either alone.
• Standing test: whether your heart-rate jump on standing has been bigger lately than it usually is.
• Consistency: missed mornings, or readings at very different times of day, which make the comparison less reliable.

When comments appear: from your 8th morning reading in the same position (7 earlier mornings plus today). Some need more: "drifting up/down" about two weeks of mornings, "more up-and-down than usual" at least 5 readings in the last week, "heart rate up, HRV down" at least 4 readings in the last week, and "bigger jump on standing" at least 6 standing tests. They are general wellness information, not medical advice.

Your data

Nothing is kept until you tap Save. Saved readings and sessions are stored in this browser on this device.

• Save to file (open any saved reading) saves that one reading, with all its beat-to-beat intervals, as a file.
• Save all to file (Settings, or the Save all button above the history list on Trends) saves every reading and breathing session, with all their beat intervals, in one backup file.
• Save as spreadsheet (Settings, or Spreadsheet on Trends) saves a CSV file with one row per reading and session: date, time, type, position, score, lnRMSSD, RMSSD, SDNN, heart rate, breathing rate, signal quality, standing-test results, and pace and swing for breathing. It opens in Excel, Google Sheets or LibreOffice. It is a summary, so it can't be imported back; keep the backup file for that.
• Settings → Import history brings a history file or a single reading file back in, for example on a new phone. Clearing the browser's site data deletes everything, so save a backup from time to time.

Moving from Elite HRV

In Elite HRV, request your data export; you'll get a download link by email. Download the .zip, then in Settings → Import from Elite HRV choose that .zip (or the .txt files inside it, one per reading). Pick the position you took your readings in.

• Readings before 11:00 that last up to 5½ minutes become morning readings; later or longer ones (open readings, meditations, guided breathing) become spot checks, so they can't skew your baseline. You can switch this off.
• Everything is recalculated from the beat intervals with Still Point's own method, so old and new readings are measured the same way and your baseline and trends are ready straight away. On clean readings the score matches Elite's HRV number; on readings with a skipped or extra beat it can differ by a few points, because the two apps handle such beats differently.
• Imported readings are marked from Elite HRV. If a batch went in with the wrong position, Remove all Elite HRV imports in the same place takes them out again. Elite's tags and moods aren't in the export, so they don't come across.

After you switch, once you have 5 mornings in Still Point, Trends compares them with your last Elite HRV mornings. If they line up, it says so. If there's a clear step, usually from a change in routine such as breathing, position, time or reading length, it explains this and offers Start my baseline from the switch date, so the old routine doesn't skew your baseline. Old readings stay in your history and charts, and you can go back to your full history at any time.

Privacy

Still Point has no server, no account and no tracking, and never sends your readings anywhere. Opening the web app is an ordinary visit to its website, like any page; after that, the only thing it ever asks that website for is a newer copy of itself, so updates arrive. The Android app has no internet permission at all.

Translating the page. If you use your browser's Translate button, the browser sends the page's text to its translation service (Google's, in Chrome). Still Point marks your readings, sessions, history and strap details so the translator leaves them out: only the app's own buttons and labels are translated.

The Android app

Still Point is also an Android app: the same app, with readings, breathing sessions and chimes that keep going while the screen is off, and no internet permission at all. It is not on Google Play; download it from stillpoint.anonacondacodelab.com/android.html, which also explains how to install it and how to check that it's the official build. When you start your first reading or session, it asks to show a notification: that notification is what keeps it running with the screen off.

The Android app keeps its own history, separate from the web app. To move your history across, use Settings → Save all to file in the web app, then Import history in the Android app. Updates install over the old version and keep your history; Settings → About → Check for updates tells you when a new version is out.

Install as an app

In Chrome on Android, the HRV tab offers Install (also in Settings → Options, or Chrome's menu → Add to Home screen / Install app). It then has its own icon, opens full screen and works without a connection; Bluetooth still needs Chrome underneath, which it uses automatically. Your readings stay the same: the installed app and the web page share the same storage.

Troubleshooting

• Connect does nothing or the strap isn't listed: close Polar Beat, Polar Flow, Garmin Connect, Wahoo and other apps using the strap, make sure the strap is worn and moist (it sleeps when dry), and that Bluetooth and location are on.
• "Heart rate only: no beat-to-beat data": the device sends your heart rate but not the time between beats, so it can't measure HRV. This is common with watches broadcasting heart rate. Breathing sessions still work and show your heart rate; for readings, use a chest strap.
• Noisy reading: moisten the electrodes, tighten the strap a little, keep still and don't talk.
• The screen turns off during a session: the app asks the phone to stay awake; keep the page in the foreground. The Android app keeps going with the screen off. If a phone still stops it after a few minutes, set the app's battery use to Unrestricted in Android's settings.

Support

Questions or problems: hello@anonacondacodelab.com. A description or a screenshot is usually enough; please don't send exported files unless you are happy to share them, because they contain your health data. Still Point is free software under the GNU GPL v3; the source code is at github.com/Anonaconda-CodeLab/still-point

Polar and H10 are trademarks of Polar Electro Oy; Garmin, HRM-Dual and HRM-Pro of Garmin Ltd.; Wahoo and TICKR of Wahoo Fitness; Coospo, Magene and Decathlon of their respective owners. Still Point is independent and not affiliated with any of them.