The brand new Apple Ultra 4, released in September, is dressed up with a new S11 chip, more AI features, enhanced heart rate sensing, and longer battery life.

Whether you’re looking to add this to your Christmas wish list or are hunting for the perfect gift for the special triathlete in your life, we tested the new Ultra 4 across swim, bike, and run to answer the question: is this smartwatch good enough for triathlon?

Let’s start with the battery life. With the Ultra 4 on my wrist for training, GPS tracking, calls and texts, and everyday wear, the charge held for just over two full days before I needed to dock it, consistent with Apple’s claim of up to 50 hours of everyday use.

On the battery topic, the Ultra 4 also introduces two new workout battery modes: Extended Workout and Max Extended Workout. The extended delivers up to 25 hours of tracking with full GPS and heart rate readings and max extended stretching that up to 45 hours while still recording GPS every second. Both involve tradeoffs: Extended Workout switches on Low Power Mode and removes running form metrics such as vertical oscillation, stride length, and ground contact time, while Max Extended also turns off alerts and splits, with other metrics such as running form and power disabled entirely. For triathletes, the extended workout mode is the more relevant addition, while the max extended is aimed at ultra runners and ultra hikers.

The second big update is the new optical heart rate sensor, which Apple says delivers the most accurate heart rate sensing in a wearable watch. Apple went so far as to release a study comparing its Series 12, which shares the Ultra 4’s new sensing system, with six competing wearables, using a Polar H10 chest strap as the reference.

With 1,254 participants contributing to the final analysis, Apple reported better heart rate accuracy overall during workouts than every competing device tested. Those findings are promising, although the study assessed the readings each device reported without detailing how often readings were missing or how long those gaps lasted.

Back to the watch – now with a look at readiness and recovery.

HRV metrics are now available for viewing in the Vitals app. You’ll need to wear the watch overnight for at least seven nights to establish your personal baseline.

For triathletes, HRV is a useful tool for tracking how the body is responding not only to training and recovery, but also to broader life stress. (You’ll often hear coaches say that all stress counts, including stress outside of training. HRV offers insight into just that: how your autonomic nervous system is responding to the combined demands of exercise and everyday life.)

Science aside, the recovery insights give you an indication of how ready your body may be to tackle the next day’s session and take on additional training load, or whether pulling back and allowing for a little more recovery might be in order.

While a wearable-based readiness score has its limitations of course, it is fun to see it actively fluctuate over the course of the day based on the inputs: quality of sleep, recent sessions, etc. – almost like real-time feedback to the demands of the day (and week, and month!).

The next two features are useful everyday additions, although perhaps less important to triathletes than the new features described above. Sound Recognition now comes to the Ultra 4, alerting you via push notifications to selected noises in the environment. Previously, your phone needed to be close by; now, the Ultra 4’s audio processing picks up the sounds without it.

The next feature is the instant Shazam recognition, which detects the music playing near you and returns the song title and artist’s name. Again, this is part of the always-on audio processing.

Rounding out the updates are Live Rewind and Siri Recap, two of the most talked-about features. These Audio Intelligence features will be released in beta later this year. The audio intelligence reminds me of the Cineplex Dolby Atmos announcement: “all around you.” It’s AI with its ears always listening.

Starting with Live rewind, a double press of the digital crown displays the last 15 seconds of a conversation as text, such as a waiter sharing the daily specials. Siri Recap, on the other hand, will allow you to read a transcription summary of a conversation via the Siri app. You choose when and where Siri Recap takes notes.

Now, in terms of security and privacy, Apple says these features process raw audio in a dedicated, isolated compartment on the watch’s chip, then immediately delete it without creating or storing audio recordings. You can chose to opt in or out to each audio intelligence feature.

So, is the Apple Watch Ultra 4 good enough for triathlon? Its feature set makes a strong case, and I’m still wearing mine. Its existing multisport tracking, longer battery life, and HRV and recovery insights make the Ultra 4 a compelling training companion.

For me, the appeal is having an all-in-one watch with fitness tracking, health data, and more alongside the ability to take calls, send texts and, of course, tell time. The new audio features are interesting extras, but the changes that matter most are the ones that keep us on track with our training.