By 10 a.m., California’s golden hills were already baking in 80-degree heat. Not exactly ideal conditions for trail running, but perfect for the endurance test I had planned – not for me, but for a smartwatch. I wanted to know if Samsung’s new trail mode on the Galaxy Watch Ultra 2 would hold up as well on trails as it looked on paper, and if it could make me a smarter trail runner (or, at the very least, a better hydrated one).
Samsung pushes the Ultra 2 further into sports watch territory with native trail running, recreational diving, and a rugged design built to take on the elements. For trail runners, the most important feature additions are offline navigation, live elevation data, and AI-powered hydration reminders.
Before leaving, I needed directions. In theory, you’ll be able to navigate nearby trails directly from the watch – a game-changer, if it actually works. In reality, the route finder handed the task over to the Samsung Health app on my phone because I didn’t have any routes preloaded. There was a “Find Route” option, but that only gave a blank map. Even zooming in on California, with its abundance of trails, no route was discovered.
My other option was to load a GPX file from a previous run. Six months ago, I had no idea what a GPX file, or GPS interchange format, was. Since then, enough smartwatch accuracy testing has left me with a small library of exported files. One of them was already 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 was hoping for, but it got me on the right track. Once the map was loaded onto the watch, I was off.
Hydration reminders may not be such a bad idea
I hadn’t even gone a kilometer when I hit the first climb. I knew it before I even looked up, because the watch announced it through the speaker. The screen showed the climb as a line graph that filled in real time as I ascended the hill, almost like a video game challenge. Even though the road ahead of me looked like an endless stone wall, I could see exactly how much pain I had left on the watch.
Once at the summit, the screen transformed into an elevation profile with a graph showing all the peaks and valleys I still had to conquer.
About half of my run was in direct sunlight around midday, so I expected the display to struggle. Instead, one of the first things I noticed was how well it handled glare. As I moved between blazing sun and tree cover, the 5,000 nit screen adjusted so easily that I never needed to squint or place my hand on it. Samsung’s display expertise (the company makes TVs, after all) really shows here, and this is one place where the Ultra 2 outperforms many dedicated sports watches.
About 30 minutes into the race, after completing two long climbs in the heat, the watch beeped with my first hydration reminder. In fact, I was drenched in sweat, so the timing was right and I would have happily taken a hydration break. But since I had swapped my water bottle for a tripod on my running bag 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, drawing on a combination of biometric data including heart rate and environmental factors such as temperature, altitude gain and workout duration. It’s a smart idea, but I’d trust it a lot more if it used a dedicated sweat sensor to measure actual sweat loss instead of relying on a prediction.
Yet in a summer marked by relentless heat waves, hydration reminders seem less like a gimmick and more like the kind of feature that could genuinely help people avoid trouble when adrenaline makes it easy to ignore the warning signs. I received two more hydration reminders at different points during my race, although I wasn’t able to rehydrate before heading home.
Even when I’m not testing running features, I avoid hitting trails with headphones in my ears. Rough terrain, loose rocks, and the occasional rustling of brush mean I want both ears to be alert. So turn-by-turn navigation through the watch’s speaker, loud enough to be heard outside, was a welcome feature on the Galaxy Watch Ultra 2.
Even though I had technically hiked this particular trail before, I didn’t remember the exact version of it, so it was good to have some guidance. Every fork in the road, every moment I veered off course, was greeted by a polite voice from my wrist reminding me to stay the course. On an unfamiliar trail, this could be the difference between staying on course and adding an unplanned uphill mile. I could also access a birds-eye view of the entire route, which showed exactly where I was on the trail and how much I still had to go.
Finish the trail with 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 almost 30% of its charge – a reminder that battery life is still an 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 with GPS, LTE, maximum brightness and hill tracking still took its toll. I haven’t yet reached Samsung’s claimed 60 hours of normal usage, although the company says battery life improves as the watch learns your habits. After two weeks, I can wear it longer than when I started testing it.
The Ultra 2 won’t replace a dedicated sports watch like the Garmin Forerunner or the feature-rich Fènix for serious endurance athletes. But after 5 miles in the California hills, it left me wanting to get back on the trails — and maybe even explore a new one once Samsung’s trail finder feature rolls out. For a smartwatch that should also handle work emails, Google Gemini and the less adventurous aspects of working life, that’s high praise.
Vanessa Main Orellana
Main writer
Vanessa is a senior editor at CNET, reviewing and writing about the latest smartwatches and fitness trackers. She first joined the brand as an on-camera reporter for CNET’s Spanish-language site, then moved to the English side to host and produce some of CNET’s YouTube videos and series. When she’s not testing the latest health technologies, you can catch her hiking or trail running with her family. See full bio