Garmin Forerunner 645 Running Watch
Garmin introduced its richly featured Forerunner 645 in January 2018. A few months later, an update added compatibility with Spotify music. This was to the delight of runners everywhere. Many of us use music as a way to focus or break up the monotony of a long slow run.
This watch has applications besides run tracking, of course. You can pay for purchases with it, so you don’t have to carry a card or cash during your outings. A wrist sensor tracks and crunches heart rate data as long as you wear the watch. GPS capability gets you where you need to go, and helps you find the way back. You also get phone notifications, and a LiveTrack feature to let friends and family know where you are.
Advanced features are a wonderful thing, and we will talk more about them later on. But the watch’s main purpose is right in the name: it tracks all the metrics of your run, going beyond speed and distance to tell you things like how much time your feet spend on the ground during runs.
If you are a runner who appreciates advanced analytics, the Garmin Forerunner 645 may be for you. Read on to learn more.
Waterproof up to 50 meters
Compatible with Spotify
Sleep tracking is automatic, does not include power naps
Can hold a charge for up to a week of daily use
Comfy non-pinching strap, low-profile design, and light weight-will forget you are wearing
Use Garmin Pay to make purchases with no card or smart phone (won't work with all POS systems)
Free apps let you customize watch face and more
Others can track your runs with LiveTrack (for safety or friendly rivalry)
Watch is not compatible with Pandora or other music players besides Spotify
Quite expensive, and advanced features have little appeal outside running community
No touchscreen, just five side buttons
Who Is It For?
Other runner-specific stats include recovery time or the amount of time it takes for your heart to return to its typical pulse rate after the activity that causes the heart rate to increase. Speedy recovery time can be an indicator of good heart health. It's an example of one of the very specific training goals this watch makes possible. Distance runners have long looked at resting heart rate as a metric for the effectiveness of their training, with a lower resting heart rate as the goal.
In addition to resting heart rate and recovery time, the optic wrist sensor also gives you heart rate zones, alerts during runs, calories burned by heart rate, and maximum heart rate post-run. There are even more heart metrics, so many that it's difficult to describe them all.
Other cool things this watch can do include ground contact time, stride length, run cadence, and a race predictor. The race predictor attempts to forecast your performance in a race based on your recent metrics during training. It's a fun way to challenge and compete with yourself, and you can also challenge friends with one of the dozens of different apps that are all compatible with the watch.
Just from looking at the most basic specs, it's obvious that the Garmin Forerunner 645 caters to serious, experienced runners. Cadence, stride length, and ground contact will not mean much to recreational runners or those of us just starting out. In this next section, we'll break down some of the specific technical stats and explore more of what you can do with this watch. If you are thinking of purchasing, though, do yourself a favor and hit the product page on Garmin's website first. It is easy to find and goes into greater detail than we are able to here.
Lens: Corning Gorilla Glass
Quick-release bands for removing or customizing the band
Silicone strap fits 5 to 8-inch wrists
1.2-inch screen with 240 by 240 resolution (in pixels)
Weighs about 42 grams with factory strap (less than 1.5 ounces)
Holds up to 200 hours of movement history
Fully functional clock with stopwatch, timer, alarm clock, and sunset/sunrise tables
9 onboard sensors, including GPS, GLONASS, Galileo, heart rate sensor, compass, gyroscope, and thermometer
Connect IQ app lets you change look and layout of watch for quick customization
Bluetooth, ANT+, and Wi-Fi compatibility
Calendar, weather (without an extra app), Find My Phone/Find My Watch safety feature
Camera remote controls the camera on your phone
Garmin Pay capability
Activity modes include indoor cardio, strength/gym workouts, yoga, and all different kinds of running. The watch will work on a treadmill as well as it will outside. These non-running activity modes are a concession to non-runners who may want to use the watch, as well as those whose center is running but who also like to cross-train.
Our only gripe about this is the yoga tracking mode. We're mostly old granola ladies, so we believe yoga practice is a time to disengage completely and clear your mind of whatever is in it by getting attuned to your body. For us, that means leaving the watch in your locker with the phone. But not everyone feels the way we do, and even we know how to turn off or disable features if we don't want them. The other great thing about this watch is how easy and intuitive it is to use, even when dealing with more advanced settings and metrics. We'll discuss more ease of use in the next section.
Ease Of Use
To confirm what we read, we looked up the 645 user's manual. It is easy to find through Google, living on the Garmin website and a number of mirror sites. However, you find it, previewing the user's manual is a great way to guide a purchase decision for this watch or most any fitness product you could want. If the directions are poorly written or overly complex, you can look elsewhere for a similar product.
A button on the top left both powers the watch on and engages the vibrant backlight which lets you read and select even in the dark. All buttons are big enough to always find, and you won't fumble and press two buttons at once. You start the activity with a button on the right and push the same button to pause activity so you can read a message or perform another non-exercise task.
You also get a back button that doubles as a split lap switch and a down button for scrolling. Finally, the bottom right button lets you see the main menu. This button also lets you access settings and widgets.
If you've ever used an old school digital stopwatch, we think you'll be able to navigate the Garmin Forerunner 645. It is exponentially more complex, but the designers made easy-touch traditional buttons to steer through it all. Don't worry, though--you don't have to read a step like "hold down button X while pulsing button 3 for exactly 7 seconds to access alarm." We've bought watches like that, too. Everything about the Garmin Forerunner 645 is intuitive and user-friendly, just as you'd expect from an industry veteran like Garmin.