With all the features of the Forerunner 230, the 235 steps it up with the addition of an optical heart rate sensor. By projecting light onto your skin, the monitor accurately measures your heartbeat without using chest strap. Bluetooth Smart compatibility handles your everyday schedule in addition to your training plan: texts, phone calls, e-mails notifications and music controls make it a veritable smart watch. The large screen displays up to 4 fields of essential metrics: current heart rate, heart rate zone, pace, distance and more. When paired with a Garmin or ANT+ heart rate strap (not included), the 235 uses the additional data coming from the chest strap to improve the accuracy of its pulse-based metrics, such as VO2 max estimates and recommended recovery times. Haptic feedback notifies you when you need to pick up or slow the pace, based on your training plan, while the integrated support for cycling sensors keeps the information flowing when on 2 wheels. For rapid GPS locating, the 235 automatically preloads satellite information based on the IP address of any computer you plug into, so you're never left anxiously waiting for a signal at the start line.