Apple Watch Ultra 4 Review: The Best Apple Watch for Training 2026

The Apple Watch Ultra 4 is Apple's most advanced smartwatch for athletes, and after four generations, the exterior remains identical to the original Ultra. All the changes are internal: a redesigned heart rate measurement system, the new S11 chip, a daily recovery score, and the longest battery life ever in an Apple Watch.

I've used the Ultra 4 as my main watch for weeks—during daily life, sleep, gym sessions, and runs. To compare heart rate, GPS, and recovery data, I wore my Garmin Forerunner 970 on the other wrist (only during some training sessions) and a Suunto chest strap. The result: this is the best Apple Watch for training Apple has ever made, but it's also the Ultra that's least distinguishable from its smaller sibling, the Series 12, and in the European Union, it arrives without several new features.

Design and Display: Familiar but Flawless

The Ultra 4 retains the same 49mm titanium case, flat sapphire crystal, and bright 3,000-nit display as its predecessor. That's not a bad thing—the design is rugged, comfortable, and built to last. The Action button and customizable orange button are still there, offering quick access to workouts and other functions.

The display remains excellent for outdoor visibility, even in direct sunlight. However, if you were hoping for a redesign, you won't find it here. Apple seems content with the Ultra's aesthetics, focusing instead on internal upgrades.

S11 Chip and Performance: A Speed Boost

The new S11 chip is derived from the A20 Pro, featuring a CPU, GPU, and Neural Engine that deliver snappy performance. With 4GB of RAM and 64GB of storage, the Ultra 4 handles multitasking and app launches with ease. The always-on processor with a secure enclave ensures that sensitive data, like health metrics, remains protected.

In practice, the watch feels responsive, whether you're scrolling through notifications or starting a workout. The improved Neural Engine also powers new features like the daily recovery score, which analyzes your heart rate variability and other metrics to give you a readiness score each morning.

Health and Fitness Tracking: A Redesigned Heart Sensor

The most significant upgrade is the redesigned heart rate measurement system. Apple claims improved accuracy, especially during high-intensity interval training and other dynamic workouts. In my testing, the Ultra 4's optical heart rate sensor matched the Suunto chest strap closely during steady-state runs, though it still lagged slightly during rapid intervals—a common limitation of optical sensors.

The new daily recovery score is a welcome addition for athletes. It provides a simple 0-100 score based on sleep, heart rate variability, and activity, helping you decide whether to push hard or take it easy. It's not as detailed as Garmin's training readiness, but it's a solid start.

GPS and Training Accuracy

GPS performance is on par with previous models, which is to say excellent. The Ultra 4 locked onto signals quickly and tracked routes accurately in urban and wooded environments. For most runners and cyclists, the GPS is more than sufficient.

Battery Life: The Longest Yet

Battery life is where the Ultra 4 truly shines. Apple promises up to 50 hours of normal use and 84 hours in low power mode. In training, you get 18 hours in standard mode, 25 hours in Extended Training, and 45 hours in Extended Training Maximum. A quick 15-minute charge provides up to 18 hours of use, which is perfect for a quick top-up before a long run.

In my testing, I easily got through two full days of moderate use, including sleep tracking and a few workouts, without needing a charge. That's a significant improvement over the Series 12 and makes the Ultra 4 a viable option for ultra-endurance athletes.

Software and Features: What's Missing in the EU

The Ultra 4 runs watchOS 11, which brings new features like Live Rewind and Siri Recap. However, these features require an iPhone 16 or later with Apple Intelligence, and they are not available in the European Union due to regulatory issues. This is a notable omission for EU users, who will miss out on some of the watch's smart capabilities.

Otherwise, the software experience is smooth and familiar. The Ultra 4 integrates seamlessly with the iPhone and offers a wide range of apps and watch faces. The new recovery score is accessible via the Health app and on the watch itself. The background to this story is set out in Moto Watch Ultra Review: A Smartwatch for Gym and Weddings. A related thread runs through Longines returns to quartz with the Conquest V.H.P., a sports and ultra-precise watch. Earlier coverage in Fluffy Apple Cake Recipe (Ultra Soft & Moist) shows how the argument developed.

Comparison with Series 12 and Garmin

The Ultra 4 is Apple's best watch for training, but it's also the Ultra that's closest to the Series 12. Both share the same S11 chip, heart sensor, and recovery score. The Ultra 4's advantages are its larger battery, titanium build, and extra buttons. If you don't need the ruggedness or battery life, the Series 12 offers similar performance for less money. A closer look at the same subject appears in Planning for Death: Why Advanced Directives Matter for Families. Anyone following the wider picture can start with Trending: latest articles. The same theme surfaces in Huawei Watch D3: Medical Blood Pressure Smartwatch Launch, which takes a different angle.

Compared to Garmin, the Ultra 4 holds its own in GPS and heart rate accuracy, but Garmin still offers more advanced training metrics and longer battery life in some models. However, the Ultra 4 wins on smart features and integration with the Apple ecosystem. Context on how this played out before sits in Google Fitbit Edge: Fitness Tracker With Display and Replaceable Battery. A companion piece, Apple Watch Ultra 4 Review: The Best Apple Watch for Training, approaches the same subject from another angle.

Key Takeaways

• The Ultra 4 is the best Apple Watch for training, with a redesigned heart sensor and daily recovery score.
• Battery life is significantly improved, offering up to 50 hours of normal use.
• The S11 chip delivers fast performance and efficient processing.
• EU users miss out on Live Rewind and Siri Recap due to regulatory restrictions.
• It's very similar to the Series 12, so consider whether you need the rugged design and extra battery.

FAQ

If you're looking for a smartwatch that can keep up with your training and daily life, the Apple Watch Ultra 4 is a compelling choice. For more fitness tech reviews and tips, check out our gaming section, where we cover the latest in wearable technology and performance gadgets.