Head to head
I ran 157 times on an Apple Watch before switching to a Garmin
Sixteen months of half marathon training on an Apple Watch Series 10, then a Forerunner 265. What the switch changed, from my own exported data.
Ask a running forum whether an Apple Watch is enough and you get the same answer every time: buy a proper running watch. It is usually given by someone who has not tried.
I trained on an Apple Watch Series 10 for sixteen months — 157 recorded runs between March 2025 and June 2026, including the block for my first half marathon. In June 2026 I switched to a Garmin Forerunner 265. This is what changed, and the honest answer is: less than the forums promise, and in a different place than they say.
One thing first, because it decides how much to trust this page. I did not wear both watches on the same runs. Two devices on one wrist for a season would be the cleaner experiment and I did not run it. What I have instead is sixteen months on one watch and then a switch, which answers a different and arguably more useful question: what happens to an actual runner who changes.
What sixteen months on an Apple Watch looked like
Not a beginner’s training block. The Apple Watch recorded 137 km in September 2025 and 154 km in November, with long runs regularly past 12 km. My fastest 10 km of that whole period — 4:36/km on 7 March 2026 — was recorded on the Apple Watch, not the Garmin.
Nothing about the watch stopped that happening. If the story were “you cannot train seriously on an Apple Watch”, sixteen months of my own data disagrees with it.
Where the switch actually changed something
Two places, and neither is accuracy.
The battery. Apple rates the Series 10 at up to 18 hours; Garmin rates the Forerunner 265 at up to 13 days. In practice that is the difference between a watch you charge daily and think about before a long run, and one you charge on Sundays. Road Trail Run’s runner review puts an hour of GPS running at roughly 10–20% of the Series 10’s battery, which is survivable — but only if charging is a habit you already have.
The lap button. Executing 6 × 1000 m means starting and stopping a lap under load, with a climbing heart rate and wet hands. The Forerunner has a physical button you can hit blind. The Series 10 has a gesture and a touchscreen, and the same review reports the double-tap being unreliable during hard efforts. Third-party apps largely fix it — you are just paying an app to restore something the cheaper watch does in hardware.
| Apple Watch Series 10 | Garmin Forerunner 265 | |
|---|---|---|
| Everyday battery | Up to 18 hours | Up to 13 days |
| GPS bands | L1 only | Dual frequency |
| Lap control | Gesture or touchscreen | Physical button |
| Charging | 80% in about 30 minutes | Days between charges |
Note what is not on that list: GPS accuracy in any form that mattered to me. The Series 10 is single-band where the Forerunner is dual-frequency, which sounds decisive and mostly is not. Road Trail Run found Series 10 traces matching a dual-band watch to within about 1% on open roads. Dual-band earns its money between tall buildings, not on a road loop through farmland.
What did not change
I can put a number on this one, because the two exports overlap in what they measure. At the same average heart rate, my pace after the switch was close to what it was before it: seventeen seconds per kilometre faster in the 155–165 bpm band, five seconds faster at 165–175, slightly slower at my easiest efforts. Over the same period my weekly volume went up by about a fifth.
In other words, the improvement I made across the switch is the improvement you would expect from training more. None of it is attributable to the watch, and I would be selling you something if I implied otherwise. The full working is in what a new Garmin’s race predictor is actually telling you.
The one thing I missed, and where I found it again
In the first weeks with the Forerunner I missed exactly one thing, and it is not on any comparison chart: decimal places.
Apple gives you cardio fitness to two of them. My export has 168 VO2 max values and 165 of them carry a decimal — 54.40, then 53.59, then 52.82. You can watch it move. Garmin shows a whole number, and mine sat on 51 for five weeks before flipping to 52.
Then I read my own Garmin export and found the decimals had been there the whole time. Garmin
stores the underlying figure as maxMet at full precision and rounds it for the screen. Multiply
maxMet by 3.5 and you get the number the watch declined to show you.
| Date | Shown on the watch | maxMet in the export | Actual VO2 maxmeasured |
|---|---|---|---|
| 27 Jul 2026 | 51 | 14.6593 | 51.31 |
| 31 Jul 2026 | 52 | 14.8382 | 51.93 |
| 11 Aug 2026 | 52 | 14.7647 | 51.68 |
| 19 Aug 2026 | 52 | 14.8721 | 52.05 |
That table also shows why the whole number is misleading in both directions. The jump from 51 to 52 at the end of July looks like a step change in fitness. It was a drift of six tenths. And the small decline in mid-August is invisible on the watch entirely.
If this bothers you as much as it bothered me, the fix costs one export: Garmin Connect → Account
Settings → Export Your Data, then look in DI-Connect-Metrics for the MetricsMaxMetData file.
What surprised me
How much of the watch is built for someone training, rather than someone exercising. The Apple Watch closes rings. The Forerunner assumes you have a race in the calendar and organises itself around it — training load, readiness, a race predictor, structured workouts waiting on the wrist when you head out. I did not know I wanted that until it was there.
Whether all of it is correct is a separate question, and the answer for at least one of those features is no — the race predictor spent its first month guessing.
What happened to the Apple Watch
It still gets worn — just not running. It is the better-looking watch, it has the strap I like, and it goes out in the evening. That is the ending most of these articles do not have: nothing was replaced. One watch took over training and the other kept the part it was always better at.
Who should switch
Stay on the Apple Watch if your week is easy runs, long runs and the occasional tempo effort, and you already charge it every night. Sixteen months of my own training says it will not hold you back. Buying a second watch will not make you faster.
Switch if your plan has structured intervals in it every week, or if you have grown tired of thinking about the charge before a long run. Those are the two things you are actually buying.
And because those are the two things, the cheapest Forerunner buys them as completely as the most expensive one. Both have the button. Both last a week.
Whichever you pick, buy on the discount. The Forerunner 265 is two generations old now and regularly reduced, and the cheaper Forerunner 170 has the same physical lap button and the same week of battery. Neither of those facts is worth paying a flagship price to work around.
Sources
- Apple, Apple Watch Series 10 tech specs — GPS bands, battery
- Road Trail Run, Apple Watch Series 10: a runner’s review — GPS comparison against a dual-band watch, battery per GPS hour, splits under load
- Garmin, Forerunner 265 product page — battery life
- My own Apple Health and Garmin Connect exports, August 2026