WRIST-BASED HEART RATE - Run without a strap - the Forerunner 225 uses a built-in sensor to measure heart rate at the wrist
GRAPHIC INTERFACE - A colorful gauge shows your zone at a glance: warm-up (gray), easy (blue), aerobic (green), threshold (orange) or maximum (red).
GPS - GPS-enabled, Forerunner 225 provides accurate distance and pace data. You can also view your run on a map when you upload to Garmin Connect.
ACCELEROMETER - A built-in accelerometer provides distance and pace data when you're running indoors, with no need for a separate foot pod
ACTIVITY TRACKING - It doubles as a watch and activity tracker. Count steps, calories and distance throughout the day. The move bar with vibration alert motivates you to move when you've been sitting too long. (sleep monitoring as well)