Carley is a writer, editor and social media professional. Before starting at Forbes Health, she wrote for Sleepopolis and interned at PBS and Nickelodeon. She's a certified sleep science coach and ...

Medically reviewed by Anisha Shah, MD Key Takeaways A heart rate over 100 bpm or under 60 bpm at rest can be ...

Apple Watch heart rate tracking now rivals medical-grade devices when settings and calibration are optimized. Using advanced optical sensors with green LEDs, Series 4 and newer models continuously ...