When it comes to adventuring, there are two running and fitness watches that really stand out. The Apple Watch Ultra 3 and the Garmin Fenix 8 Pro. Here’s how they compare.
Both the Garmin Fenix 8 Pro and the Apple Watch Ultra 3 models are designed with extreme sports and outdoor activities in mind and include the durability and emergency features to provide peace of mind off the piste.
With an incredible wealth of workout and activity modes, the most advanced health and fitness data, exceptional displays, markedly improved battery life and bleeding edge GPS positioning, it’s worth splashing out on these top-rated fitness watches.
Let’s see how they square off against each other.
Display
The Apple Watch Ultra 3’s rectangular display offers 3,000 nits of brightness from its 422 by 514 wide-angle OLED panel that sits inside a 49mm titanium case. The brightness drops as low as 1nit for ultra-low light environments and the variable refresh rate goes down to 1Hz to help maximise battery life. There’s also a Night Mode for certain watch faces like Wayfinder and Orienteering.
The highest-end Fenix 8 Pro offers a circular 51mm casing housing a microLED touch-friendly display capable of hitting 4,500 nits. That’s the highest brightness rating of any outdoorsy watch. It’s that little extra boost in the sunniest of conditions and it’s great at a number of viewing angles. A resolution of 454×454 offers perfectly crisp text too. There’s also a Red Shift mode that alters the display hue to go easier on the eyes during the evenings. The AMOLED version of the Fenix 8 Pro is still incredibly capable and is significantly cheaper.
Battery life
This one isn’t a fair fight. If you’re planning on staying in the wild for more than a couple of days, then you’ll want a Fenix 8 Pro.
In pure smartwatch mode (meaning without GPS and with the always on display disabled) you’ll get 27 days of battery life. With GPS and heart rate broadcasting you can get 80 hours before a recharge. “No other fitness watch I’ve tested this year comes close,” wrote our reviewer in late 2025.
The Apple Watch Ultra offers an advertised 42 hours of varied use, which it defines as “600 time checks, 180 notifications, 30 minutes of app use, a 60-minute workout with music playback from Apple Watch via Bluetooth, and 6 hours of sleep tracking over the course of 42 hours.”
It’ll get you three days in low power mode. 14 hours total with GPS and heartrate readings. So yeah. No contest.
Durability and emergency features
You’re buying one of these expensive watches with the knowledge it could get dinged up a bit or exposed to extreme conditions. So how do they hold up?
The rugged design of the Fenix 8 Pro adds a little girth, but the titanium casing and crystal sapphire glass are notoriously tough. In fact they’re among the toughest naturally occurring materials on earth. There’s a 10 ATM water resistance rating, making it suitable for swimming and it’s dive-certified for up to 40 metres.
As well as the rock solid multi-band GPS, the Fenix 8 Pro also offers LTE connectivity so you can make calls, send messages and share live location. Sending SOS messages via satellite is also possible, but all of the additional connectivity fatures requires a subscription to Garmin InReach.
Initiating the SOS sounds an alarm to help the emergency services pinpoint your location and the watch has a powerful built-in flashlight for those night hikes and camping trips, with a red LED light for emergencies.
The Apple Watch Ultra offers the same construction materials of “aerospace-grade” titanium and sapphire crystal. You’ll benefit from Emergency SOS messaging via satellite that’s available at no extra cost, and 5G connectivity is available too. The cellular connectivity is better than Garmin’s as you can use it to stream/download music and podcasts.
There’s also the benefit of Apple’s fall and crash detection technologies to help you out in an emergency. An 86-decibel siren can be heard from up to 600m away and Medical ID data is accessible by first responders.
Apple offers what it calls the ‘most accurate GPS in a sports watch’ but should you get lost, there’s access to offline Maps, a handy Backtrack feature that guides you to retrace your steps, wayfinder creation and an automatic check-in feature that lets a loved one know when you arrive at your destination. The Apple Watch Ultra 3 is rated for 100m of water resistance but shouldn’t be used at depths greater than 40 metres. It’s IP6X dust resistant and there’s also a flashlight.
Health and fitness
Garmin caters for extreme and elite athletes at this price point. If you’re looking for something to track your runs, a simple Forerunner costing a fraction of the price will suit.
Both that and a Fenix 8 Pro will also provide data like Body Battery, Training Status, Training Readiness, Recovery Time, Training Load, Training Effect, Suggested Workouts Vo2 Max, heart rate and power zones, race predictor, body temperature, Sleep Score, HRV and loads more. There are coaching plans, custom route creation among the navigation features.
Garmin offers dedicated workout modes for tens of exercise styles and the granular metrics are all fed back to Garmin Connect. The Fenix 8 Pro also offers an ECG for heart health readouts. There’s also Active Intelligence for AI-infused insights into sleep, stress, training and more through Garmin Connect+ (paid).
The Apple Watch Ultra 3 offers workout modes for countless activities and consumer-friendly features like Workout Buddy offering personalized audio motivation. The Race Route enables you to race against your previous best time, while Pacer keeps you on track to hit a PB. It’ll also automatically transition between your multisport workouts, making it a good option for triathletes.
Many of the Garmin metrics like HRV, Vo2 Max, Training Load, heart rate and power zones, detailed sleep tracking with a Sleep Score, running dynamics and plenty more, but it’s nowhere near as comprehensive as Garmin’s offering.
In terms of health features the Apple Watch Ultra 3 does a little better, with hypertension alerts, sleep apnea alerts, irregular heart rate alerts, cycle tracking, bloody oxygen, and an ECG you can take at any time.
Additional Features
The Fenix 8 Pro offers music syncing over WiFi, Garmin Pay, smartphone notifications, and third-party apps and watchfaces from the IQ Connect store. Personally I find the smartwatch-style features to be more of a nuisance than an assistance, so have those phone notifications turned off.
The Apple Watch is a much more rounded smartwatch to match its health and fitness chops and naturally syncs up well with an Apple iPhone (that being said it’s a non-starter if you operate on Android). There’s the wealth of the App Store offering access to apps like Strava, Nike Running, Peloton, MySwimPro, as well as Apple’s stock line up. There’s Apple Pay, built in access to Apple Music and Podcasts too.
Price
The Apple Watch Ultra 3 starts at $799 / £749. The Garmin Fenix 8 Pro maxes out at $1,700 / £1,400 for the 51mm microLED model. However, the smaller 47mm AMOLED model is $1,200 / £990.
