Sorry, your smartwatch isn't as accurate as you think
Heart Rate Monitors: How They Work and Accuracy
Monitor your heart rate with Apple Watch - Apple Support
How to measure heart rate on your smartwatch - The Verge
8 tips for accurate heart rate reading via your smartwatch - Coolblue - anything for a smile
Best heart rate monitors 2023: Improve your fitness and track heart health - Wareable
Smart Watch for Men (Alexa Built-in & Bluetooth Call), 1.8" Smartwatch with SpO2/Heart Rate/Sleep/Stress Monitor, Calorie/Step/Distance Counter, 100+ Sport Modes, IP68 Fitness Watch for Android iOS: Amazon.co.uk: Electronics & Photo
10 Best smartwatches for heart patients: Discover top picks with essential fitness-tracking features | Mint