Garmin's New Forerunner Is King of Wrist-Mounted Trainers

Garmin's newest wrist-top fitness watch is a 50-megaton blast forward that combines the best of the company's past two Forerunner models — the 305 and 405 — but easily laps both on almost all counts. Like its predecessors, the 310XT uses GPS to track your runs and rides, but it adds so much more to the equation that it feels like a breakthrough device rather than an upgrade.

Triathletes in particular will love this watch — it's certainly the best triathlon timekeeper we've yet tested. Not only does it sync up with your ANT+ power meter to display watts as you roll along on the bike, but the auto-multisport mode also lets you switch from one sport to the next by hitting the lap button, and it times your transitions to boot. And this wrist mounted wonder isn't some aqua-phobic wussy either: The new waterproof body can stand up to steady dunking, you can also take it swimming, kayaking, surfing and rowing without fear of turning it into a brick.

Garmin has shrunk the guts of this baby enough that it looks almost like a standard, if very odd, watch. Metrosexuals might give it a pass, but soul-sucking hipsters could probably get away with wearing it in public.

Setup is dead simple. When you first fire it up the watch walks you though a series of questions, and inputs all of your basic data. We did have a bit of trouble getting it to recognize our heart-rate strap initially, but resolved that within a few minutes without having to make a call to tech support or engage in an extraordinary amount of cursing.

In addition to the heart rate monitors and power meters, it will also sync up with Garmin cadence sensors to track your bike crank's RPMs, and to footpods if you want to measure your running cadence on a treadmill or the trail. If you fancy racing in both on road and Xterra events, you'll be pleased with the multiple presets for different bikes, allowing you to have one weight setup for your mountain bike and another for your road rig. Overall the interface is easy to use and intuitive, although it takes a little more tinkering and RTFMing than other Forerunner models.

When it comes to performance tracking, the new 310XT is so strong we expected it to fail a drug test. It tracks just about every fraction of workout data you'll need to know, gives you instant feedback and keeps a history file on the watch that can also upload to Garmin Connect (more on that in a bit). Power, calories, heart rate, speed, distance, elevation: You name it, they're all there. It can also help make your workouts more effective. You can easily set up custom interval workouts right in the watch. A vibrating alarm lets you know when you've gone certain distances or drop out of heart rate or speed zones. The tactile feedback is fantastic, not only because it keeps you from having to glance at the watch, but also because it means you can wear headphones and still stay informed, or receive alerts on a group run without bugging your pals.

But when you do want to peep, you can customize the display with up to four data fields for each screen, and swap between multiple screen presets so you can keep your top tier data like speed, heart rate, time and distance on one screen. Then swap to another for secondary metrics like elevation, grade and calories burned.

Because each sport supports up for four screens, this means you can keep track of at least 16 metrics for each sport — making you the biggest nerd in the race if not the fastest competitor. New features like in-watch heart rate graphing, power tracking, and nautical speed and distance tracking are also impressive.

The watch can be charged up either with a wall plug, or by connecting it to your computer's USB port. A progressive meter indicates the amount of charge when the watch is turned off — a nice feature that lets you know if you've got enough juice to hit the road for a few hours or not. Garmin claims the watch will take you through a heart-stopping 20 hours of training on a single charge. We were too pooped to work out that long, but we did manage to squeak in more than six hours of activity with a lot of button pushing and still left the battery 64 percent full.

One thing we couldn't test was what happens when you get home. This Forerunner is designed to wirelessly sync your workouts with the Garmin Connect website. However, we couldn't test data uploading as the Garmin Connect website isn't set up to receive data from 310XT model Forerunners yet (unless you're behind the Garmin corporate firewall, that is). We'll check back when it's up and running, and update this review as necessary to reflect that.

This Forerunner is the king of training tools, and among the best heart-rate, speed and distance tracking wrist tops we've seen in the past several years. Having said that, for elite and pro level athletes, it doesn't offer the kind of complex heart rate monitoring and stride feedback available on the Polar RS800CX, which we recently reviewed. But for most athletes simply seeking a personal best, the Forerunner 310XT will take you there in stride.