Best for Training
When BACKPACKER editors dream, it's about reassignment to the Anchorage field office, heels that never blister, and a GPS small enough to fit on your wrist yet powerful enough to track routes and hold satellites in deep woods. Alas, only the third part of that dream is coming true, say testers who used the Forerunner all summer and fall. "At 2 by .75 inches, it's only 10 percent fatter than the chunkiest altimeter watches," reports one editor, "yet it's no mere watch. It's a powerful training tool that delivers altitude, heart rate, speed, distance, and other useful workout data."
Battery life spanned 15 hours per charge, and we locked onto satellites in less than 30 seconds under open skies. Back home, you can generate route maps and training charts after wirelessly uploading trips to your Mac or PC, then share workouts via email and social networks (like Facebook). One editor credits the Forerunner for helping him notch his best 10k time ever and fine-tune a training plan that got him to Mt. Rainier's summit. The only thing this unit doesn't do is let you navigate using onscreen topos (though you can save routes and waypoints for later editing). Best for: outdoor athletes who want GPS-based speed and distance, HR stats, and multiple data screens with customizable views, but don't need full navigation functions. $350 ($399 with heart-rate strap); 2.7 oz.; garmin.com.
The rugged, waterproof Forerunner 310XT boasts up to 20 hours of battery life, packaged in a slim design with a flexible wristband. Forerunner 310XT tracks time, distance, pace, elevation and heart rate, and it syncs wirelessly through ANT+ technology with Garmin heart rate monitors and foot pods, compatible third-party fitness equipment and power meters, and the users PC or Mac for automatic data download. Plus, it goes from wrist to bike in seconds with the optional quick-release wrist and bike mounts.