Overview
A Physiological Load Episode is Grio noticing that your heart rate stayed unusually elevated while you were not doing anything, and that the HRV evidence supports real physiological load rather than a sensor artifact.
It is a bounded recent event, not a verdict on your recovery, and detection is best-effort near-real-time rather than continuous: Apple Health delivers data in the background on its own schedule.
Separately, a fixed High Stress Alert can announce a sustained high-stress run. It is a product notification rather than a coach message, and it does not create a chat message.
How it’s calculated
What is collected
Your device reduces supported Apple Watch observations into five-minute buckets before anything is uploaded. A bucket may carry aggregate heart rate, aggregate HRV, sample counts, steps, exercise minutes, workout overlap, time bounds, timezone, source, and observation time, and nothing else. Raw HealthKit samples never leave the device and are not retained after aggregation. These buckets expire after a bounded retention window.
Episode eligibility
- A personal, time-matched, low-activity baseline with at least seven valid days. Before that, nothing is eligible.
- Movement, an active workout, and the post-workout period suppress eligibility: They explain the elevation.
- Preferred evidence: sustained elevated heart rate for at least 15 minutes, plus a lower-than-baseline HRV observation in or immediately around that window.
- Fallback evidence: a much stronger heart-rate elevation sustained for at least 30 minutes, when no contemporaneous HRV exists. An HRV value that is present and not low blocks this path. Missing HRV is uncertainty, not evidence of a drop.
Contact rules
Contact is event-based and conservative. A new episode becomes eligible only after the preceding elevation has resolved during low activity, and the family may contact you at most twice per local date. Quiet hours, global contact budgets, reachability, expiry, deduplication, and delivery-time validation all still apply. A late workout, or any other evidence that invalidates the episode, cancels the contact rather than delivering a stale interpretation.
When it does contact you, it opens the main conversation with one restrained observation and one check-in question. The copy describes what was observed, preserves the uncertainty when HRV was unavailable, and must not assert a cause or a psychological state. It may name the Stress Band you can already see as supporting context.
High Stress Alerts
The alert path has its own arithmetic:
- Three contiguous High stress intervals (15 measured minutes) establish an alert episode: One fixed push may announce it.
- Six contiguous scored non-High intervals (30 measured minutes) must follow before another episode can alert. When that measured recovery completes, one push may announce the return to baseline.
- Never during activity: While inactive, a sustained High run must also be corroborated by the physiological-load detector. After activity, a separate delayed-recovery alert becomes eligible only after 30 minutes, and only with corroborating HRV evidence or extreme scores.
- At most three distinct high-stress episodes per local date, only between 07:00 and 22:29, and never more than 30 minutes after detection.
- Movement, missing evidence, and immature-baseline intervals break a new High run and never count as recovery.
Rest and Low bands never contact you on their own without a preceding established high episode. Tapping an alert opens the Stress page for that date.
Edge cases and fallbacks
- A watch that rarely produces HRV falls back to the longer, stronger heart-rate-only path.
- An episode invalidated after the fact is cancelled, not corrected in place.
- A positive Condition Check-In suppresses recovery contact for the episode.
How to read your score
An episode says one thing: something raised your physiological load while you were still, and it lasted. It does not say what. The honest list of causes for the same pattern includes illness, alcohol, poor sleep, a hard previous day, caffeine, a stressful hour, and a warm room.
This is also why an episode is a conversation opener rather than a headline number. The evidence supports “worth a look,” not “here is what happened.”
What to do with it
- Answer the check-in question: the coach asks because your account is the only thing that can distinguish the remaining causes.
- Treat a repeated pattern as the real signal: one episode on a Friday evening is life. Four episodes across a week during quiet afternoons is worth changing something for.
- Do not read an episode as permission to push or to stop: it never automatically changes a committed Daily Plan or a durable goal, and neither should it change one silently on your behalf.
Troubleshooting & FAQs
- Can Grio tell me I am getting sick?
- No, and it will not try. It can say that your heart rate stayed unusually elevated during low activity and that the HRV evidence did or did not support physiological load. Illness, alcohol, a hard previous day, and ordinary life stress all produce that pattern. Naming one would be a diagnosis Grio is not making.
- I was sitting still and stressed, but nothing was flagged. Why?
- The bar is deliberately high. Eligibility needs at least seven valid days of your own time-matched low-activity baseline, then either 15 minutes of sustained elevation with supporting HRV, or 30 minutes of a much stronger elevation when no HRV was recorded. An HRV reading that is present and not low blocks that fallback entirely.
- How do I turn the alerts off?
- The high-stress alert setting is on by default and is an explicit opt-out in settings. Coach contact about recovery is governed separately by the recovery-change control, which is also default-on. Quiet hours and contact budgets apply to both.