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COVID-19 & HRV (N=1 Data)
Wearable devices can detect COVID-19 onset 4 days before symptoms, with HRV declining significantly and taking weeks to recover.
N=1 Evidence
- Brian Eisenberg: Wearable detected HRV/RHR decline 4 days before positive test
- Mayo Clinic author: COVID mid-way through 300-day protocol
Wearable-based early illness detection is well-replicated across Oura, WHOOP, and Apple Watch.