Keeping tabs on run-savvy metrics and loaded with Garmin Pay for cashless convenience, the Garmin Forerunner 645 GPS helps you get the most out of every run, regardless if you're training for an upcoming marathon or simply getting back in shape after a long, cold winter. You'll enjoy a host of useful running features, such as wrist-based heart rate monitoring, plus advanced running dynamics when you pair it with Garmin's Running Dynamics Pod (sold separately). Additionally, Garmin's Training Status tools monitor your running history to let you know if you're on track with your training goals, as well as monitoring your training load to prevent overexertion. Seeing you'd rather leave your wallet at home while running, the Forerunner 645 GPS features Garmin Pay for wireless payment convenience simply by waving the watch in front of a compatible payment machine at your local diner, gas station, or store. Besides wireless payment compatibility, it's loaded with ANT+, Bluetooth Smart, and Wi-Fi capabilities, so you can wirelessly sync it with a host of compatible devices, including iPhone and Android smartphones. And speaking of wireless syncing, it works seamlessly with Garmin's Connect app, so you can view all your exercise stats on a smartphone or computer for an in-depth analysis of your running stats and exercise output.