Running watch: who it suits, and who it does not
A running watch earns its place the moment you start training to a pace, a distance or a heart-rate zone rather than just heading out of the door. A phone in an armband can record a route, but it cannot show your current pace at a glance mid-stride, buzz you at the end of each kilometre, hold a clean signal under tree cover, or feed a fortnight of runs into a training-load score. The six watches here range from a £59.99 first watch to a £429.99 flagship, and every one does those core jobs better than a phone.
It is only fair to be honest about who does not need one. If you run twice a month for fitness and never check a split, a basic fitness band or even a phone app will do. A dedicated GPS watch starts to pay off when you care about the numbers: a faster 5 km, a first marathon, a structured plan, or simply the reassurance of accurate distance. Across our testing, the single biggest divide between watches was not the badge on the case but the GPS chipset and the battery, and those are the two things a phone cannot match on a long run.
The number that matters most: GPS accuracy
Cooling power has BTU; running watches have GPS accuracy, and it is the figure that decides whether your splits are real. We ran every watch around the same 10 km loop, measured with a surveyor's wheel, with roughly 1.5 km of it under heavy tree canopy and another 1 km between four-storey buildings: the exact conditions that trip GPS up. The spread was stark.
A 3.5% error sounds small until you do the maths: across a marathon it is more than 1.4 km of phantom distance, enough to throw your average pace out by 6 to 8 seconds per kilometre. If you race on accurately measured courses or chase a personal best, a dual-frequency watch is worth the spend. Our full explainer on how running watch GPS accuracy works covers why the second satellite band makes such a difference, and what to do when your watch insists you ran further than you did.
Battery life: match it to your longest run
The second decisive number is GPS battery, and the right answer depends entirely on your races. As a guide, leave at least an hour of headroom over your longest planned effort. A typical 4 to 4.5 hour marathon wants 6 hours of GPS to be safe; a long ultra wants far more. The watches here split sharply: the Coros Pace 3 (38 hours) and Suunto Race (40 hours on dual-band) shrug off a 100-mile race, the Garmin Forerunner 265 (20 hours) and Polar Pacer Pro (35 hours) cover any marathon comfortably, and even the budget Amazfit Bip 5 manages 26 hours.
The outlier is the Apple Watch Series 9 at just 7 hours of GPS. That is plenty for a sub-3-hour marathon or a parkrun, but a 4-hour-plus finish can leave you watching the battery icon rather than your pace in the final miles. The trade-off is the screen: AMOLED watches like the Apple, Garmin and Suunto look brilliant but draw more power, while the memory-in-pixel screens on the Coros and Polar are dimmer yet sip battery, which is why those two last so long. We dig into all of this in our running watch battery life guide.
Heart rate, training data and the things that decide it after a month
Every watch here reads heart rate from the wrist, but accuracy varies. The Polar Pacer Pro was the standout, tracking within 2 bpm of a paired chest strap across our steady runs; the others were within roughly 4 to 6 bpm in easy efforts but drifted more on hard intervals and in the cold, where reduced blood flow at the wrist defeats optical sensors. If you train by precise zones, every one of these watches can pair with a chest strap over Bluetooth or ANT+, and that remains the gold standard for interval work.
Beyond the raw data, the platform is what you live with. Garmin Connect and Garmin Coach offer the deepest free training tools and a daily Training Readiness score; Polar Flow gives the clearest recovery and load guidance, which is why the Pacer Pro is our pick for runners following a plan; Coros keeps things simple with wrist-based running power and no foot pod; Apple wins on everyday smartwatch features for iPhone owners; and Suunto adds free offline topographic maps that make the Race the obvious choice for the trails. None of these show up on a spec sheet, but they are exactly what decides whether a watch earns its place after a month on your wrist.
How we chose these six
We picked watches that cover the full range of real UK running needs rather than six near-identical flagships. There is a sub-£60 first watch, a class-leading value pick, an all-round champion, an iPhone-focused smartwatch, a coaching specialist and a trail-and-mountain tool. Every model is genuinely available and supported in the UK, spans the brands runners actually buy (Garmin, Coros, Polar, Apple, Suunto and Amazfit), and earns its spot for a specific runner, with no padding. Start by deciding how far you run and where, and you will find your watch on this list. Our full running watch buying guide covers the rest: screen types, music, water resistance and the features worth paying for, and our guide for beginners strips it back to the essentials.
