garmin forerunner 620 – gear review


large numbers, small form factor and clean design mean the Garmin Forerunner 620 works as a plain watch.

Even though I’ve had mixed feelings about the quality of Garmin products, especially the heart rate strap, I decided to try out the new Garmin Forerunner 620. It has some intriguing features and looks nice. And to be honest switching to a Polar or Suunto would mean too much trouble. I’ve invested a few years in Garmin and Garmin Connect. Migrating all my data and learning a different platform is just not worth my time at the moment.

I’ve always had medium range Forerunners because the top of the line watches were just too bulky and expensive. Now that the new Forerunner 620 is out, I’m finally able to wear a watch that is both functional and fairly stylish.

The first few runs with the new watch gave me some poor readings, showing over a minute slower pace than usual, and much shorter distances. I was thinking I had received a dud. Luckily it turned out to be a
conflict with the foot pod on my shoe. After taking that off all is functioning well.


I’m not that fashion conscious but have been steering away from the usual bulky brick watches with ugly protruding knobby buttons. I’ve been waiting for a sports watch that has all the features I need in a smaller form factor. The 620 finally meets these requirement. I wear the watch as an actual watch when I’m not running. How novel is that? It’s similar aesthetically to the newer smart watches out there. I dare say it looks even nicer than a Pebble watch.


Garmin did a great job with the interface, striking the right balance between buttons and touchscreen. The touchscreen feature is thankfully not just another gimmick. It compliments the buttons and lets you quickly get to relevant data. The learning curve for most sports watches is usually steep. Not so with the 620. Scroll up and down the menu by touching the upper or lower part of the screen, confirmation is a simple tap on the middle of the screen. The screen is also surprisingly responsive once you understand where to touch.

garmin 620 charging
much easier to charge and upload data

charging and upload

The USB charger slaps easily onto the back of the watch with the help of magnets, a welcome improvement over the Forerunner 210 that has a cumbersome 4 pin clamp that hardly ever connects properly. The battery is good for 10 hours of activity. That’s not enough for the longer ultra races, but I don’t do more than a couple of those a year anyway. As a normal watch the battery will of course last for days. So far I’ve only needed to charge it once a week.

Uploading data to Garmin Connect goes either through the USB connector or through wifi. I’ve so far had mixed results with connecting to my home network. Not sure what’s up with that, will troubleshoot when I have time. A recent firmware update might have resolved this issue.

heart rate data and breast strap

So far so good with the new breast strap, the heart rate readings seem in line with expectations. I won’t go into much detail about my issues with past Garmin straps. I’m hopeful they have dealt with the issues. It looks like they’ve added one more contact point for more accurate readings.

sensors and extra features

Garmin have moved some sensors around. The foot-pod that was used for cadence readings has been replaced by a sensor in the watch. And there are more readings coming from the breast strap. I have mixed feelings about this. I realize they can’t store all the sensors in the watch itself and get accurate enough readings. But I don’t wear the strap on every run, perhaps only every 10th run just to make sure I’m running within my target heart rate. I run more by feel these days. This means I’m missing out on the extra sensor readings of the new 620. A minor grip I know, can’t win them all. Eventually the sensors can be made small enough that they can be surgically installed under my skin. (just kidding!)

garmin connect running dynamics charts
new readings, cadence is now taken care of with a sensor on the watch instead of a foot pod

Running dynamics
There are two interesting new readings, vertical oscillation and ground contact time. More movement vertically is an indication of energy being used in the wrong direction. Bouncing up and down like a ball is not exactly efficient when the goal is to propel the body forward. The same goes for ground contact time. I have fairly good readings across the board here, still some room for improvement though. Ground contact time is less than optimal. I think increasing my cadence by a few steps per minute should fix this issue.

These readings tend to fall apart on uneven terrain though, especially on trails. The flatter the course the better the readings, so I’ll be using the breast strap on the track once or twice a month. The readings are related to running efficiency and comparing them over time during consistent conditions is the only way to make good use of this data.

garmin 620 review race prediction
the race predictions are a good estimate, just 3 minutes off on the marathon, a little slow for the 5K

Race prediction – I’m pretty impressed with this because the predictions are fairly close even though I’ve only got a handful of runs with the new watch. And these were all just easy, low intensity jogs. But for all I know Garmin is using all my data on Connect from past training runs and races and not just from recent 620 data.

Recovery time – I already have a good feeling for how much time my body needs to recover so have only looked at a couple of the suggestions. They fell in line with what I was expecting. After a long easy run of 2 hours it was recommending a 24 hours rest period. Makes sense.

Vo2 Max – I’ve never had my V02 max tested before, so don’t know if this is accurate. I have a pretty high reading for someone my age, so I suppose that’s encouraging. Not sure. It will be interesting to see if I can push the number further up. I may also go to a lab at one point to test myself just for kicks.

v02max garmin connect
Vo2Max of 50 is not bad for an old man

not so good

– The watch is not connecting as fast to the GPS, sometimes I have to wait over 5 minutes before it gets a lock. If you take off running and hope it connects eventually you may have to wait several miles before it does and it will give you horrible readings up to that point.

– The watch is consistently shorting my mileage on the treadmill. About one mile per minute slower than what the treadmill is telling me. Not a big issue.


I recently installed a new firmware update that I hope addresses some of these issues. I really don’ have too many gripes with the 620. I’m so far happy with the device with the new data provided.

Is all this going to make me run faster? A little. It helps the big picture, but the best way to get better at running is to go out and run, not sit and stare at charts and graphs.