Optical vs chest strap heart rate monitors - Measuring beats per minute using different sensors
Wrist-worn optical and chest strap heart rate comparison in a heterogeneous sample of healthy individuals and in coronary artery disease patients | BMC Sports Science, Medicine and Rehabilitation | Full Text
Best heart rate monitor: Watches to chest straps | The Independent
The 13 Best Heart Rate Monitors
Heart rate measurement: chest strap vs pulse measurement - Coolblue - anything for a smile