Designed to be fully compatible with a heartrate monitor and power meter, the 920XT is just as impressive when used as a standalone training partner. It measures sleep and calories burned, so you can calculate your base metabolic needs. Added to that, it counts swim strokes, drills, and distance for laps. It even features a metronome that helps you to keep your stroke or cadence at your optimal speed, for those days when your mom isn't following you blowing a whistle. When paired with the included HRM Run heartrate monitor andor an optional power meter, the 920XT jumps to the next level of wow. Not only will it estimate VO2, it even has the ability to know how long your feet stay on the ground during your run to assist with running form metrics. If that isn't smart, what is Using any of Garmin's ANT power meters, you're able to receive the full list of power metrics through the 920XT. The Garmin 920XT also has smart alerts for emails and texts so you can seem like you're working when you're really getting in that second run. The 920XT weights a mere 61 grams, and given all the features, we think that's pretty impressive. The battery lasts up to 24 hours in training mode and 40 in UltraTrac mode. And of course, it also has a standard watch mode. Outside of all the features you can possible use in training, Garmin also is a part of the virtual world of Garmin Connect. The 920XT connects via a smartphone app, computer or even wirelessly. It uploads your workout files and allows you to track your training and compare data with friends. It also is compatible with the Russian GLONASS system so you won't get lost if you're ever on a long run in Siberia.