Read the live Sentinel card

What this does

The live card is Sentinel’s cockpit. Every figure on it comes from your body, since Sentinel reads physiology and has no view of your positions. It is called Sentinel · Live on the web and sits at the top of the Sentinel screen in the apps.

The LIVE badge lights when a reading arrived in the last 30 seconds, with the name of the device that sent it. No badge means nothing has come in recently.

The state badge, session timer and an alerts pill sit alongside it. See Session states and bio stress.

Four vitals:

• Current heart rate in beats per minute, with a deviation readout underneath such as “+18.4% above baseline”. The deviation text is colour graded on its own scale: green under 10%, yellow from 10% to 20%, red over 20%. It grades the size of the gap and ignores the direction, so a 25% drop below baseline is red too.
• Bio Stress, reading Low, Medium or High. It comes from the same deviation figure but uses a wider scale than the text above it, at 15% and 30%, and a reading below baseline is always Low. The two are meant to differ. See Session states and bio stress.
• Session Avg, your average heart rate since this session started.
• Baseline, your personal resting figure, with a freshness stamp such as ”45s ago” or “3m ago”.

The chart is a rolling 60 minutes of heart rate, coloured by zone, with a marker wherever an intervention fired. Its zone labels read “Deeply calm”, “Cooling down”, “Warming up”, “HR climbing” and “High stress zone”. Clicking an intervention in the list under it highlights that marker.

Before a session starts, every vital shows --. That is the idle state, not a fault.

Before you start

The card shows the same session everywhere. Whichever surface you read it on, you are looking at one session record, so numbers match across your phone, the web and a tablet.

On the web the quick stats bar above the tabs shows Status, Interventions Today and Rules Active. Rules Active always shows two dashes. It is not wired to anything. Count your enabled rules on the Rules tab instead.

HRV does not appear on the vitals grid. It reaches your rules and your baseline, and only devices that send beat-to-beat data provide it live.

Steps

What you should see

During a session: a LIVE badge with your device named, a heart rate that changes every few seconds, a timer counting up, and a chart line extending to the right.

The baseline freshness stamp should read seconds or minutes, not hours. An old stamp means readings have stopped arriving.

Between sessions: -- in all four vitals and an idle message. On iPhone it reads “Start a session to see your live heart rate”. While a device is connecting you may see “Waiting for heart rate…” or “Reconnecting”.

If it doesn’t work

The timer runs but the heart rate stays at --. The session is live and no readings are arriving. Check the phone app is open and the wearable is connected.

The LIVE badge keeps dropping out. Readings are arriving more than 30 seconds apart. On WHOOP or Fitbit Air the phone screen is locking. See Why WHOOP and Fitbit need your phone unlocked.

The deviation looks wrong. It is measured against your baseline, and an uncalibrated baseline uses a safe default rather than your own resting rate. See The baseline and its 20 sessions.

Rules Active shows two dashes on the web. Known, and it never shows anything else. Use the Rules tab.

Related

• Session states and bio stress
• The baseline and its 20 sessions
• Start and stop a Sentinel session
• Intervention history