Most smartwatches don’t last for more than a few hours of connected running with GPS. Dedicated GPS watches do much better. Polar’s newest training watches could be ones to look for, based on their promised battery life alone: the new Vantage V lasts a whopping 40 hours with GPS and heart rate on, Polar says.
Both the Vantage V and the lower-end Vantage M have all-new heart rate sensors, using a green and red LED array and new metal contacts that use skin contact to help maintain heart-rate accuracy. Polar claims the improved sensors will work better across skin types, through hair and sweat, and even while swimming. The watch’s heart-rate sensing isn’t made to be EKG-accurate, but it’s designed to work with multiple sports.