Fix a problem with the app

This is almost always a missing permission — and there are two separate ones to check, because the iPhone and the Apple Watch each ask for Health access on their own.

On iPhone: Settings app → Privacy & Security → Health → Cardio Protocol, and make sure Heart Rate is turned on.

On Apple Watch: open the Watch's own Settings app (not your iPhone) → Privacy & Security → Health → Cardio Protocol, and turn on Heart Rate and Active Energy. If Cardio Protocol doesn't appear in that list at all, fully open the app directly on the Watch (tap its icon, rather than only glancing at a complication) and check again afterward.

If both permissions are already on, make sure the Watch band is snug against your wrist and give the sensor 10–15 seconds after starting a session to lock on. If you're using a Bluetooth chest strap instead, confirm it's paired and powered on before you start.

Voice coaching only speaks for the heart-rate-based protocols (Zone 2, Norwegian 4x4, Tabata, Wim Hof) — 12-3-30 doesn't use heart rate, so there's nothing to coach against. Check that your device isn't in Silent Mode or set to a very low volume, and confirm Health permissions above are granted, since coaching needs a live heart rate reading to work from. It also speaks only on a zone transition plus periodic check-ins by design, not constantly — if you're steadily in zone, it may simply have nothing new to say.

Make sure the Watch is unlocked, on your wrist, and within Bluetooth/Wi-Fi range of your iPhone. Force-close and reopen Cardio Protocol on both devices, and if a session seems stuck mid-sync, restarting the Watch usually clears it.

Sessions under 60 seconds are treated as accidental taps and discarded automatically rather than cluttering your history. Right at that edge, the app will ask whether to save or discard it — if you don't see that prompt, the session was likely just below the threshold. Separately, saving a session at all requires an active subscription or free trial — if the trial has lapsed, start it again from the app's paywall to resume saving sessions.

Check iPhone Settings → Face ID & Passcode (or Settings → Cardio Protocol) → Live Activities is allowed, and confirm Low Power Mode isn't on, which can suppress Live Activities system-wide.

Use "Restore Purchases" on the paywall screen if you've reinstalled the app or switched devices while signed in with the same Apple ID. To view, change, or cancel a subscription directly: iPhone Settings app → your name at the top → Subscriptions → Cardio Protocol. After starting a free trial, give the App Store's purchase sheet a few seconds to confirm — the paywall closes automatically once it does.

Confirm iCloud Backup is turned on in Settings on both the old and new device, and that you're signed into the same iCloud account on both. Restoring can take a minute to sync after reinstalling — give it a moment before assuming it failed.