Photo: Greg Broom
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The Basics and Buying
Garmin Forerunner 910XT
Timex Ironman Run Trainer
The GPS brains of the RCX5 sit in an external unit that slips neatly into a pocket or the included armband. This gives the watch the sleekest form and longest battery life in our roundup — a claimed 11 months. It also means there’s a good chance you’ll sometimes forget the GPS pod (or lose it altogether). We learned this the hard way when, during a triathlon transition, we left the sensor in our bike pouch. Thanks to Polar’s proprietary wireless interface, this watch can monitor heart rate underwater (unique among those we tested), which opened a new area of analysis for our swim sessions.
get-gadget Easiest interface in our roundup. Watch vibrates when your heart rate strays from the target range.
TIRED Chest strap moves around during fast swim laps. Not ANT+ compatible. Dim backlight.
$350 | Polar RCX5