Garmin Forerunner 620

Garmin is on a high at the moment. The products that the GPS specialist has brought to market over the last couple of years have been, for the most part, top notch. The Garmin Edge 810 cycle computer that I reviewed last year became my partner on every ride, and was only replaced recently. And even then, it was replaced by the new Garmin Edge 1000 (full review soon), which raises the bar even higher than its predecessor.

Likewise, the Garmin Forerunner 220 that Sandra reviewed back in January proved to be a commendable addition to the Garmin running range, offering a surprising array of features at a very reasonable price. And now I’m looking at the Garmin Forerunner 620, which sits at the top of Garmin’s tree of running computers.

The Forerunner 620 is packed with features, some of which I haven’t seen on a running watch before. It’s also incredibly light and very comfortable to wear, but is that enough to make it the high-end GPS running watch to buy?

What’s in the box?

It’s probably more important to start with what’s not in the box. What you won’t find is any form of bike sensor, because unlike its predecessor (the Garmin Forerunner 610) the new 620 doesn’t support ANT+ bike sensors, and has no cycling mode. So, if you’re looking for a multi-sport watch from Garmin, your only choice is the Forerunner 910XT, which will probably be a bit hardcore for anyone who isn’t competing in triathlons regularly.

But while some may be disappointed that the Forerunner 620 only tracks your running, I can assure you that it fulfils that duty with aplomb.

Garmin Forerunner 620

In the box you’ll find the Forerunner 620 itself, which is almost unbelievably light compared to most other GPS watches – it weighs only 43g in case you were wondering. It feels almost too insubstantial in the hand, but once you’ve strapped it to your wrist, you’ll appreciate its featherweight nature.

The charging cable has a standard USB port on one end and a docking cradle at the other. The cradle has magnets embedded into it so the Forerunner 620 literally snaps into place when close by. It’s definitely more convenient than plugging a USB cable in, but as always with proprietary cables, it means you’ll have to carry it with you if you think you’ll need to charge your device.

Talking of charging, it’s best to keep the FR 620 sitting in its cradle when you’re not using it, because Garmin’s estimates on battery life are somewhat ambitious. Garmin claims 10-hours of use and up to six weeks in low-power watch mode, but in reality you’re not going to get near either count. To be fair, the battery life is dependant on the features you’re making use of, but I’ll dig into that a bit later.

Although you can use any ANT+ heart rate sensor with the Forerunner 620 the one that comes in the box is a bit special. You see as well as measuring your heart rate, the bundled sensor also has a built-in accelerometer that measures the movement of your torso and captures a plethora of useful data.

Garmin Forerunner 620

There’s also a new chest strap to go with the new heart rate sensor. As well as the usual rubber electrodes that need wetting before you set off, there’s a “contact patch” that should also be moistened. I assume that this makes for a more accurate reading, and given that I didn’t experience a single spike or dropout while using the device, it’s safe to say that it works.

Getting Started

The Forerunner 620 isn’t the most unobtrusive sports watch I’ve come across, but it isn’t as large and chunky as others either. If you go for the blue and black model that I’ve been testing, you can get away with wearing it every day without it screaming its credentials.

If there’s one disappointment with the design, it’s the screen size. Despite the watch face itself being quite large, the actual screen area is far smaller, since there are touch sensitive controls placed on wide surrounding bezel – to the left of the screen is the “back” touch-button and to the right of the screen is the “menu” touch-button.

There are also four traditional buttons surrounding the edge of the watch. At the top left you’ll find the main power button, which doubles as the backlight button. The top right button is the start/stop control, while the bottom left button will instantly display the time-of-day, no matter what data screen you might be viewing at the time – very handy.

Garmin Forerunner 620

The bottom right button will mark a new lap while you’re running, while also syncing your watch with Garmin Connect when you’re not running. To do the latter your watch needs to either be paired to your phone or your Wi-Fi network. The Wi-Fi connectivity is particularly useful, since you can just hit the Sync button when you get home and your run will automatically upload whether you’re paired with your phone or not.

It is worth pairing with your phone, though, because just like the excellent Garmin Edge 810 cycle computer, the Forerunner 620 supports LiveTrack. LiveTrack lets you share your run with friends and followers in real-time. You simply download the Garmin Connect app to your phone, pair the FR 620, then select LiveTrack before you set off.

You can configure LiveTrack to email specific people, or simply share your run via Twitter. Anyone clicking the link in your LiveTrack announcement will be able to watch your run on a map – it’s pretty handy if your partner is trying to figure out when you’ll be home for lunch!

It’s worth bearing in mind, however, that keeping the FR 620 paired with your phone, and sending all that LiveTrack data up to the web portal does have a pretty significant impact on battery life. As I said earlier, battery life with the FR 620 is entirely dependant on the features you choose to use – especially the wireless features.

As with most Garmin devices, you have lots of flexibility when it comes to the data screens. You can configure up to four data screens that you can swipe between while you’re running. Each of those data screens can have up to four fields of data, and you can decide what goes into each of those fields.

Garmin Forerunner 620

Customisation is something that Garmin has always done well, and the FR 620 lends itself to personalisation perfectly. And even if you go for the full four fields per screen, each field is still large enough to see at a glance.

So, you can set screen one to be your time, distance, heart rate and time of day, while screen two is your current lap time, average lap time and distance into the current lap. There should be more than enough options and permutations to keep even the most obsessive live data junkie happy.

Taking it to the VO2 Max

One of the most interesting new features in the FR 620 is its ability to estimate your VO2 Max – essentially your maximal oxygen consumption while your body is under aerobic load. Although a truly accurate VO2 Max measurement requires a controlled environment – usually a sports lab with a treadmill and real-time measurement of oxygen intake – you can get a reasonable estimation based on heart rate under aerobic load.

The Forerunner 620 will automatically calculate your estimated VO2 Max as long as your run lasts in excess of 10 minutes, and you’re wearing the heart rate sensor. When you finish your run the FR 620 will present you with your VO2 Max – the higher the number, the fitter you are.

Garmin Forerunner 620

As well as giving you a number, the FR 620 will also present you with prediction data based on your VO2 Max estimate – you’ll get estimated times for 5km, 10km, half marathon and full marathon runs. Of course these estimates are just extrapolations from the base VO2 Max data, and don’t, by any means indicate that you should attempt a marathon – I know I won’t be doing so anytime soon!

Calculation of VO2 Max data isn’t something new in a sports watch. Polar has been doing this for years, using its Own Index calculation, but the way in which Polar gathered the data is very different. While the Garmin Forerunner 620 is estimating oxygenation while you’re running, the Polar method required you to measure your heart rate at complete rest.

How the VO2 Max estimate is achieved isn’t important though. What is important is that it’s a good metric by which to judge progress and improved fitness over time. It’s also fun to see if you can actually hit those race predictions made by the FR 620.

As well as predicting what your race performance could be, the Forerunner 620 uses the data it collects from each run to estimate your recovery time. When you’ve finished running the FR 620 will tell you its suggested recovery period – this could be anything from 24-hours up to a few days.


Obviously it’s up to you whether you take that suggested recovery time on board. I was frequently told that I should rest three days after a 15km run, which wasn’t going to happen. However, when you start your next run, the FR 620 will take note of your heart rate and pace over the first couple of km, and then tell you whether it thinks you’re fully recovered enough to carry on.

Running Dynamics

Another new, and very interesting feature that the Forerunner 620 brings to the table is Running Dynamics. Remember that accelerometer that’s built into the heart rate sensor? This is where it comes in handy.

Having an accelerometer built into a sports watch is nothing new. In fact pretty much every activity tracker relies on similar technology to measure steps throughout your day, while more serious sports watches use it to track distance when running indoors. However, by placing an accelerometer in the sensor mounted on your chest, Garmin has opened the door to a whole host of new data.

There are three aspects to Running Dynamics, and it’s entirely up to you which one you focus on. The idea is that the data collected can help you improve your technique and ultimately how efficiently you run.

Garmin Forerunner 620 Running Dynamics

The most commonly understood aspect of Running Dynamics is Cadence, which essentially measures how many steps you’re taking per minute. If you’re a cyclist as well as a runner, you’ll be all too familiar with the concept of cadence and how important it is to efficiency.

The most common, generally accepted ideal running cadence is 180 steps per minute, but obviously fore-foot strikers will naturally have a shorter stride and take more steps than heel-strikers.

Having switched back to heel-striking at the end of last year (that’s another story) I’m well aware of the temptation to over-stride when trying to increase pace. When I started using the FR 620 my cadence was around 160spm, which put me just about in the green. What really surprised me, though, was just how hard it is to increase your average cadence without making every run feel like a marathon.

With a lot of effort I’ve pushed my cadence up to around 168spm, but it really does feel like I’m taking more steps than I should. Hopefully it will start to feel more natural for me, or perhaps it’s time to move onto a different Running Dynamics metric.

Garmin Forerunner 620

The second metric is Vertical Oscillation, which measures how high you’re rising with each step of your run. The higher you bounce, the less efficient your technique – not only does that vertical movement take effort, but it’s also movement in the wrong direction. Reducing your vertical oscillation is a good step (no pun intended) to a more efficient stride.

Finally there’s Ground Contact Time, and as the name suggests, this measures how long you’re spending on the ground during each step, measured in milliseconds. The longer you spend on the ground, the longer you’re not launching yourself forward, so try and think like a rotary engine, rather than a traditional vertical piston engine – you know it makes sense.

Garmin Connect

The Garmin Connect online portal has gone through a well needed overhaul recently. The original version is still there if you prefer it, or can’t quite get your head around the new Modern implementation, but it’s definitely worth persevering and getting to know the new system.

The new Garmin Connect is split into two main areas – Sports and Health & Fitness. The latter focuses primarily on the Garmin vivofit activity tracker (review coming soon), and allows you to track your daily activity at a glance. You can also pull in nutritional data from My Fitness Pal, giving you a clear idea of what calories are coming in, and how many you’re burning off.

But for this review we’re focusing on the Sports part of the equation, and here’s where you’ll find all the data from your Forerunner 620 and, in my case at least, my Edge 810 and more recently Edge 1000.

Garmin Connect

You can sync the FR 620 with Garmin Connect via many routes. You can send the data over the smartphone app while you’re out and about, you can just hit that Sync button when you’re in range of your home Wi-Fi network, or you can slap the device into its cradle and plug it into your computer. Whichever way you do it, all your data can be analysed and obsessed over online.

And there’s a truly dizzying amount of data to dig into – pace, distance, average pace, calories, elevation, heart rate etc. You also get your run overlaid on a Microsoft Bing map, and all that cool Running Dynamics data is presented too.

The new Garmin Connect is definitely an improvement, but I’m something of a Strava convert these days, so I tend to upload the data from my Garmin devices directly to my Strava account, which enables me to easily compare to previous performances and the performances of thousands of others over the same routes.


The Garmin Forerunner 620 carries a recommended price of £359.99 with the heart rate sensor, but it’s not hard to find it online for under £300 (Amazon has it for £294). That’s a pretty reasonable price for a sports watch stuffed full of as many cutting edge features as this one.

However, many may still expect multi-sport support at this price, and it does feel like a bit of a missed opportunity by not offering a cycle mode like the old FR 610. But if you’re a runner, first and foremost, you’re far more likely to appreciate the enhanced feature set that’s relevant to your chosen pursuit, and you’d be hard pushed to find a watch that gives serious runners more data and insight to work with.

Update: I’ve just installed the latest version 2.90 firmware onto the Forerunner 620 and it does indeed now include a cycling mode. You can switch between running and cycling using the Activity Profile setting. Once you’ve applied the Ride profile, you’ll then have the option to pair the Forerunner 620 with your bike sensor, giving you speed and cadence, although speed is obviously calculated via the GPS too. This is a welcome addition, and will definitely make the price tag a lot more palatable since you’re now getting a running watch and a cycle computer.


  • Lightweight
  • Very comfortable
  • VO2 Max estimate
  • Recovery time indicator
  • Customisable screens
  • Touch-screen interface
  • LiveTrack is still a brilliant feature
  • Syncs well with Garmin Connect app
  • Wi-Fi support makes syncing at home easy
  • Running Dynamics is a great feature
  • Vibrate alerts are always welcome


  • It’s only for running
  • Proprietary charging cable
  • Maybe too much data for some

Price: £294

Manufacturer: Garmin