What Is HRV — and Why Every Health Tracker Obsesses Over It (A Plain-English Guide)
Last updated: April 2026 | Category: Health If you own an Oura Ring, WHOOP, Apple Watch, or Garmin, you’ve seen the number: HRV. Some mornings it’s high and your device says you’re ready to crush the day. Other mornings it’s low and it suggests you rest. But what is HRV actually measuring — and does…