Nereus Data wellness

Track Your Recovery Practice

sauna. cold plunge. breathwork.

Apple Watch + iPhone 7 environments HealthKit native Garmin Connect IQ

Built for Every Recovery Environment

Dry sauna, steam room, infrared sauna, hot tub, cold plunge, cold shower, and red light therapy. Each with tailored thermal dose tracking.

Real-time heart rate, HRV, and workout tracking directly from your wrist. Works with Ultra depth gauge for water temperature.

Reads and writes workout data, heart rate, HRV, and resting heart rate. All data stays on-device in Apple Health.

Guided breathing patterns during sessions. 4-4-6-2 recovery breathing with haptic cues on Apple Watch.

Earn XP for every session. 10 levels from Initiate to Legend, 13 milestones, and streak bonuses to keep you consistent.

Companion app for Fenix, Forerunner, Venu, and Enduro watches. Full session tracking with FIT recording and phone sync.

Track sessions from your phone with ambient sound detection, barometric sensing, and AirPods motion data.

Multi-environment sessions with automatic segment tracking. Switch between heat and cold within a single workout.

HRV trends, resting heart rate, heart rate recovery, and weekly activity charts to track your progress over time.

Local-first data All session data stored on your device. No cloud accounts required.

HealthKit on-device Health data never leaves Apple Health. We read and write, never upload.

Anonymized analytics PostHog product analytics with no PII. Sentry crash reports with no user IDs.

Open FAQ Every feature explained. No dark patterns, no hidden data collection.