By 10 a.m., the golden California hills were already baking in 80-degree heat. Not exactly ideal trail running conditions, but perfect for the endurance test I had planned — not for me, but for a smartwatch. I wanted to know whether Samsung’s new trail running mode on the Galaxy Watch Ultra 2 would hold up as well on the trail as it looked on paper, and whether it could make me a smarter trail runner (or, at the very least, a better hydrated one).
Samsung is pushing the Ultra 2 further into sports watch territory with native trail running, recreational diving and a rugged design that’s built to take on the elements. For trail runners, the biggest feature additions are offline navigation, live elevation data and AI-powered hydration reminders.
Before heading out, I needed a route. In theory, you’ll be able to browse nearby trails directly from the watch — a game changer, if it actually works. In reality, the route finder handed the task off to the Samsung Health app on my phone because I didn’t have any routes preloaded. There was a “Search for a route” option, but that only yielded an empty map. Even zooming in on California, with its abundance of trails, didn’t surface any routes.
My other option was a GPX file from a previous run. Six months ago, I had no idea what a GPX, or GPS exchange format, file was. Since then, enough smartwatch accuracy testing has left me with a small library of exported files. One happened to already be loaded on my Samsung Galaxy phone: a familiar 5-mile loop through the regional park behind my house. Most people won’t have that head start. It wasn’t the seamless experience I’d hoped for, but it got me on the trail. Once the map was loaded on the watch, I was off.
Hydration reminders might not be such a bad idea #
I wasn’t even a mile in when I hit the first climb. I knew before I even looked up, because the watch called it out through the speaker. The screen showed the ascent as a line graph that filled up in real time as I went up the hill, almost like a video game challenge. Even though the road ahead looked like an endless wall of rock, I could see exactly how much suffering I had left on the watch.
Once at the summit, the screen changed to an elevation profile with a graph showing all the peaks and valleys I had yet to conquer.
About half my run was in direct sunlight near noon, so I expected the display to struggle. Instead, one of the first things I noticed was how well it handled the glare. As I moved between blazing sun and tree cover, the 5,000-nit display adjusted so smoothly that I never had to squint or cup my hand over it. Samsung’s display expertise (the company does make TVs, after all) really shows here, and it’s one place where the Ultra 2 outshines many dedicated sports watches.
About 30 minutes into the run, after grinding through two long climbs in the heat, the watch buzzed with my first hydration reminder. I was, in fact, drenched in sweat, so the timing felt about right and I would’ve gladly taken a hydration break. But since I’d traded my water bottle for a tripod on my running pack that day to shoot some footage of the watch, the reminder mostly fell on deaf ears.
The Galaxy Watch Ultra 2 uses AI to estimate sweat loss, pulling from a combination of biometrics including heart rate and environmental factors such as temperature, elevation gain and workout duration. It’s a clever idea, but I’d trust it much more if it used a dedicated sweat sensor to measure actual perspiration loss instead of relying on a prediction.
Still, in a summer marked by relentless heat waves, hydration reminders feel less like a gimmick and more like the kind of feature that could genuinely help people from getting into trouble when adrenaline makes it easy to ignore the warning signs. I got two more hydration reminders at different points during my run, though I wasn’t able to rehydrate until I made it back home.
Even when I’m not testing out running features, I avoid hitting the trails with headphones in my ears. Rough terrain, loose rock and the occasional rustle in the brush mean I want both ears alert. So having turn-by-turn navigation come through the watch’s speaker, loud enough to actually hear outdoors, was a welcome feature on the Galaxy Watch Ultra 2.
Even though I’d technically already run this particular trail before, I didn’t remember the exact version of it, so it was nice to have the guidance. Every fork in the road, every moment I drifted off course, was met with a polite voice from my wrist reminding me to stay on course. On an unfamiliar trail, that could be the difference between staying on course and adding an unplanned mile uphill. I could also swipe over to a bird’s-eye view of the entire route, which showed exactly where I was on the trail and how much I still had left to go.
Ending the trail run on an empty tank #
By the end of the 5-mile run, I was parched, dusty and ready to call it a day. The watch wasn’t far behind. It had burned through nearly 30% of its charge — a reminder that battery life is still one area where the Ultra 2 trails dedicated sports watches, many of which last a week or more on a single charge.
Samsung increased the battery capacity from 590 mAh on the original Ultra to 800 mAh on the Ultra 2, but a demanding trail run with GPS, LTE, maximum brightness and climb tracking still took a noticeable toll. I’ve yet to reach Samsung’s claimed 60 hours of normal use, though the company says battery life improves as the watch learns your habits. After two weeks, I can wear it for longer stretches than I could when I started testing it.
The Ultra 2 isn’t going to replace a dedicated sports watch such as the Garmin Forerunner or the feature-packed Fènix for serious endurance athletes. But after 5 miles in the California hills, it made me excited to get back out on the trails — and maybe even explore a new one once Samsung’s trail-finding feature rolls out. For a smartwatch that’s also expected to handle work emails, Google Gemini and the less adventurous parts of work life, that’s high praise.