TomTom Runner Cardio
The draw: Strapless heart rate monitoring
No need for a chest strap with the Runner Cardio. A sensor embedded in the watch detects changes in blood flow by shining a light through your skin. When cinched tightly, it reads heart rate accurately. The GPS-enabled run computer has a four-sided button underneath the easy-to-read display and is Bluetooth ready to connect wirelessly to your phone. You can customize your workout with heart rate zones, intervals, speed or distance goals, and a race mode allows you to compete against your previous efforts.