I raced a half marathon with the Garmin Forerunner 970 vs Coros Pace 4 — here’s the winner

Garmin Forerunner 970 vs Coros Pace 4
(Image credit: Future)

I rate the Garmin Forerunner 970 and Coros Pace 4 as the two best running watches on the market — the Forerunner 970 is top overall, and the Pace 4 offers the most value — and I’ve been using both for the past few months while training for the London Marathon.

Before London comes around, however, I have some shorter races to tackle, including the Hoka Semi de Paris, which I ran at the weekend, clocking a new PR of 1:09:30.

I wore the Pace 4 and the Forerunner 970 for the race to test out their GPS and heart rate accuracy, along with how on the money the watches were with their race predictions. Here’s what happened.

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Garmin Forerunner 970
Garmin Forerunner 970: was $749 now $649 at Amazon

The Garmin Forerunner 970 is the best running watch you can buy in my opinion, with a lightweight, sturdy design and all the features you could ever need. It's rarely in sales but right now one color of the watch is reduced to $649 at Amazon

Coros Pace 4
Coros Pace 4: $249 at Amazon

The Pace 4 comes in either black or white and with either a silicone or nylon band — I'd go for nylon to make the watch even lighter. It's perfect for runners and triathletes who want a small, accurate watch with a bright display.

Predicted Race Times

Garmin Forerunner 970 vs Coros Pace 4

(Image credit: Future)

The race predictions on any watch or app are based on you running in perfect conditions, both in terms of the weather and other external factors, and your own condition, which could be influenced by illness or a lack of sleep.

I did enjoy near-perfect conditions in Paris, with chilly but not-too-cold weather for the race, and woke up feeling well-rested and in good shape to chase a PR. The course had some ups and downs though, and a mild uphill in the last mile did feel tough on the day.

Before the race the Coros Pace 4 suggested I could run a time of 1:09:12, whereas the Garmin was far more pessimistic, giving my predicted time as 1:11:10. Chalk that up as a win for Coros.

Garmin Forerunner 970 vs Coros Pace 4

(Image credit: Future)

Interestingly after the race both watches revised my predictions slightly, with the Pace 4 now giving a predicted time of 1:09:03 and the Garmin 1:08:42.

In the past Garmin predictions have proved slow to react to real-world race times, so it’s good to see a quick adjustment to a time that’s more in line with what I ran.

GPS Accuracy

Garmin Forerunner 970 vs Coros Pace 4

(Image credit: Future)

The GPS accuracy of both watches was incredibly good. They both finished with a total distance of 21.13km/13.12 miles, which is almost exactly the official race distance of 21.1km/13.1 miles.

The course wasn’t too busy with runners around me, so I was able to run the tightest racing line most of the time, and although there were some turns and a short tunnel in the center of Paris, the overall route was quite clear and simple, so it’s good to see both watches nail it.

Paris Half GPS track

(Image credit: DC Rainmaker Analyzer)

When looking at the GPS tracks from both they are almost identical throughout the race, with just one minor quirk from each early on. The splits were also coming in close to the official kilometer markers on the course throughout, making it easier to pace my run using the watches.

Heart Rate Accuracy

Garmin Forerunner 970 vs Coros Pace 4

(Image credit: Future)

For the best heart rate accuracy in training I generally use a chest strap with both watches, but on race day I relied on the optical HR from the watches and both produced very similar results.

Without a chest strap to compare them to I can’t be 100% on the accuracy of the results, but both watches produced exactly what I’d expect from my HR in a race — a gradual rise overall with some ups and downs as I ran over the small uphills and downhills on the course.

Paris Half HR

(Image credit: DC Rainmaker Analyzer)

The Pace 4 had what I think is an erroneous spike early in the race, and the Forerunner 970 rose higher than I’d expected right at the end, but the HR readings were in line with what I expect to see and what I have seen when using a chest strap in past half marathon races.

Verdict

Coros Pace 4 vs Garmin Forerunner 970

(Image credit: Future)

I can’t fault either watch for their accuracy on race day, though Coros does get a nod for having the more accurate race prediction ahead of the half marathon.

When it comes to tracking your training, both are excellent options and the Pace 4 is significantly cheaper than the Forerunner 970, which is why I consider it the best value running watch out there.

The Forerunner 970 does offer a more durable and attractive design with a bigger screen, plus extra features like maps and more in-depth training analysis. It’s a better overall watch if you don’t mind the higher cost, but on race day, you can certainly rely on either option.


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Nick Harris-Fry
Senior Writer

Nick Harris-Fry is an experienced health and fitness journalist, writing professionally since 2012. He spent nine years working on the Coach magazine and website before moving to the fitness team at Tom’s Guide in 2024. Nick is a keen runner and also the founder of YouTube channel The Run Testers, which specialises in reviewing running shoes, watches, headphones and other gear.


Nick ran his first marathon in 2016 and became obsessed with the sport. He now has PBs of 2hr 25min for the marathon and 15min 30sec for 5K. Nick is also a qualified Run Leader in the UK.


Nick is an established expert in the fitness area and along with writing for many publications, including Live Science, Expert Reviews, Wareable, Coach and Get Sweat Go, he has been quoted on The Guardian and The Independent.

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