How to Use Athlytic with Eight Sleep

Athlytic builds its Recovery and Exertion scores from Apple Health data — above all, overnight HRV. Eight Sleep measures exactly that, every night, but never writes HRV to Apple Health. So Athlytic either shows no recovery score or leans on whatever wearable you also happen to sleep in. Two minutes of setup fixes it permanently.

The setup

1. Install Nocturne and sign in with your Eight Sleep account (full step-by-step here).
2. Choose "Full Time Series" HRV export. Athlytic reads individual HRV samples from Apple Health — the same format Apple Watch writes — and calibrates your personal baseline from them.
3. Backfill with Bulk Export so Athlytic has your history for an accurate baseline on day one.
4. Enable Auto Sync — each night's data is in Apple Health by morning, so your recovery score is ready before your first coffee.
5. In Athlytic, confirm Apple Health permissions for HRV, heart rate, respiratory rate, and sleep.

Why mattress HRV works so well for recovery scores

Overnight HRV — measured while you're still and asleep — is the cleanest recovery signal there is, which is exactly why recovery apps prioritize it. The Eight Sleep sensor grid samples it continuously all night. The only thing it was missing was a path into Apple Health; that's the gap Nocturne closes. More on how the measurement works in Eight Sleep HRV explained.