> For the complete documentation index, see [llms.txt](https://docs.tryterra.co/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.tryterra.co/faq/help-topics/data-api-sdk/provider-coverage-and-per-provider-data-availability/stress-data-samples-and-fields.md).

# Why does stress data have no samples array?

**Detailed stress samples are currently only available from Garmin.** Oura and Apple Health expose only summary stress values (for example `high_stress_duration_seconds`, `rest_stress_duration_seconds`, `stress_rating`), so their `samples` array is empty.

Stress duration fields are time spent in each band:

* rest
* low (26-50)
* medium (51-75)
* high (76-100)
* `activity_stress_duration` for periods where activity made measurement unreliable

`avg_stress_level` and `max_stress_level` are on a 1-100 scale (`-1` = insufficient data). `stress_rating` is provider-specific and currently only Oura, so many fields are null on other providers.

For a cross-provider measure, Terra offers a unified [stress score](https://docs.tryterra.co/user-engagement/health-scores) product.