Spartan Sport Wrist HR Is A Sports And Adventure Watch With Optical Heart Rate Sensor admin January 29, 2017 gadgets 117 accuracy of heart rate monitoring systems have always been questioned. but not now. Suunto hopes to quell those with the Spartan Sport Wrist HR. It features an optical heart-rate sensor from Valencell, a highly respected company in the field. its mainly meant for people who workout regular;y.Optical heart rate sensor is an addition to existing features like ability to track activity across 80 different sports, GPS-route navigation and smartphone integration.