Review: watchOS 4 breathes new life into fitness side of the Apple Watch

Ars tests watchOS 4 on an Apple Watch Series 2—is the update worth it?

WatchOS 4 officially became available to all Apple Watch owners last week even if its release was overshadowed by the hype surrounding the Series 3 Apple Watch. The newest software update for Apple’s wearable brings a decent amount of change, but it’s not enough to make the Apple Watch feel like an entirely new machine. Some of the biggest new additions in watchOS 4 include a new vertical Dock, new Siri and Toy Story watch faces, a slew of new heart rate monitor calculations, and new Music and News apps.

While watchOS 4 is available for all Apple Watch models, I primarily tested it on an Apple Watch Series 2. Though we also spent time trying the new Series 3 Watch, I wanted to see how much of an impact watchOS 4 has for those who stick with an existing Apple Watch rather than upgrading to the newest model. And no matter which version of the Apple Watch you have, they’ll all feel similar running watchOS 4.

Dock and interface

You won’t notice many differences on watchOS 4 when first booting it up on your Apple Watch. Your preferred watch face fills the entire display. Swiping down from the top opens the notification drawer, swiping left or right changes the watch face, and swiping up from the bottom opens the Control Center. The Control Center now has a new feature, the flashlight switch, and it has three controls: one that puts a bright white rectangle on the display, one with a flashing white rectangle, and the last with a bright red rectangle. Apple explained the flashing option could be useful when you’re doing outdoor activities at night like walking the dog or running. Reflective clothing makes it easier for cars to see you in the dark, and the flashing option can almost act as a similar warning to surrounding vehicles if you’re not wearing that kind of clothing.

A single press of the Digital Crown reveals the app grid, while a long press brings up Siri. (Note: we’ll discuss the new Siri watch face in the next section, but discussions of Siri’s new voice on the Apple Watch are in our Series 3 review.) The app grid hasn’t changed much, but now you have the option to get rid of it. Force Touching the app grid lets you choose between grid and list view, so if you’ve hated meandering around the grid to find that one app you need, you can now keep every app in an alphabetical list.

A single press of the side button brings up the Dock, and a long press lets you either turn off the watch or call emergency services. Apps in the Dock are oriented vertically, a switch from the horizontal orientation in the previous software. It’s slightly easier to scroll by swiping up and down on the watch’s display rather than right to left, so it’s only a marginal improvement. This works even better with the Digital Crown, which you can turn to cycle through the Dock’s apps. You can also see more apps with the vertical Dock: apps are stacked on top of each other like cards in a deck, and the watch’s display can show up to three apps at once. One appears farther away in the background, one is in the middle of the display, and the other appears in the foreground.

Another new feature you may notice sporadically has to do with alerts. When your iPhone receives two alerts at the same time that get pushed to your Apple Watch, the watch combines those notifications into a single bubble. Previously, each alert had its own push and bubble, so this consolidates that a bit to make seeing multiple, immediate notifications easier.

Watch faces and complications

Everyone gets excited about new watch faces even if they represent a fraction of what’s new about a software update. After all, they’re often the most looked-at things on a smartwatch. And faces are even more important on an Apple Watch since you can have multiple watch faces on your device at one time, switching between them freely by swiping from side to side on the display.

WatchOS 4 brings three main new watch faces: Kaleidoscope, Toy Story, and Siri. The Kaleidoscope face is neat because it essentially warps an existing image into a funky, kaleidoscope-like pattern using the primary colors in the image. Apple has a few new floral wallpapers to choose from in iOS 11, and those are the default photos to use in the Kaleidoscope watch face. You can choose another image from the Photos app on your iPhone to customize the Kaleidoscope face even more. When on the watch’s screen, the face subtly moves like an actual kaleidoscope would, giving it a psychedelic effect.

The Toy Story watch face is divided into four different preferences: you can choose to have Woody, Buzz Lightyear, and Jessie appear randomly on your screen, or you can choose your favorite of the three characters to populate the watch face every time. I stuck with the group preference, so I saw a photo of three of them on my watch face most of the time, and when I tapped the watch face, different animations of the three characters popped up. Sometimes a confused Woody would run across the display, sometimes a self-assured Buzz would appear from the bottom edge. It was a surprise every time, and I don’t blame anyone who gets lost tapping away at this watch face to see all the different animations.

Apple touts the new Siri watch face’s ability to be proactive in showing pertinent information to your life. When activated, the watch face changes periodically to show you important information based on the time of day, your location, and your most used apps. I consider it the “personal assistant” watch face since it updated me on what’s going on currently in my day and what’s up next in addition to fielding questions. By default, the Siri watch face has the new Siri complication at the top-left space and the time on the top-right space. (Complications, you’ll recall, is the term Apple uses for the functional wrinkles users can swap in and out of a base watch face.) The lower portion of the watch’s display is taken up by changing information—mine typically showed me the next appointment up on my calendar, a photo from my Photos app, the latest headline from Apple News, or the podcast currently playing on my iPhone through the Now Playing complication.

Like other watch faces, you can edit the two available complications in the Siri watch face. If you don’t want immediate access to Siri all the time, you could remove that icon and replace it with a more useful app. I don’t use Siri a ton, but it did come in handy for basic information, like the weather forecast ahead of my weekend trip to Boston or the score of the Jets-Dolphins game from the previous Sunday. I like getting quick answers on my wrist, but more often than not, I have follow-up questions to my initial, easy questions. Those tend to make me reach for my iPhone rather than rely on Siri, who will ultimately ask me to open my iPhone anyway. The Siri complication was the least useful part of the Siri watch face for me, so I’m happy to have the option to switch it out for a more useful complication in the Apple Watch iOS app.

You can also edit where the Siri watch face gets its data in the Apple Watch iOS app, though only to a certain extent. You can toggle data sources on and off in the watch face’s settings page, but Siri is limited to only native Apple apps. For example, the details of the podcast playing on my iPhone will show up on the Siri watch face through Apple’s new Now Playing complication, not my preferred podcast app Overcast (even though I have the Overcast Apple Watch app installed). In that example, tapping the Now Playing card on the Siri face brings up the Now Playing controls, including rewind/fast forward 30 seconds, play/pause buttons, and a volume adjuster.

By contrast, the Overcast app doesn’t include volume controls, but it does have the 30-second skip buttons, the name of the podcast and episode title, a favorite button, and a list button that lets you switch to any other podcast episode you’ve downloaded to your iPhone. I see the practicality of the Now Playing complication, and it’s especially useful for Overcast audio because Overcast doesn’t have an Apple Watch complication (only a full app). However, I prefer controlling my podcasts with the Overcast app and wish I had that option.

I have plenty of third-party apps that I prefer to Apple’s native services, but many of them tie in to those services (like Calendar) nicely. Because of this, the Siri watch face was fairly helpful for me throughout my busiest days. However, if and when I wanted to interact with the apps on the watch (or on my iPhone, for that matter), I always reverted back to my preferred third-party apps rather than the Apple apps pushed on me through the Siri watch face.

You can make a watch face out of any image in the Photos app, and some might find the results even better than the official new watch faces. Entering the “share” settings on a single image in the Photos app brings up a new “create watch face” option. That will export the image to the Apple Watch app on iOS where you can then customize it further by adding more photos (if you want the face to be a multi-image gallery) and choosing and arranging the complications on the final watch face.

As mentioned earlier, the Now Playing complication is new in watchOS 4, and there are updates to a few other complications. The heart rate complication now shows your most recent heart rate reading and how long ago it was taken (as long as it has enough room on the watch’s display). The Messages complication has a small number inside the message bubble to indicate how many unread texts you have. The Now Playing complication has the most practical use out of all these, and arguably it gives you the most reason to interact with the watch’s display. But I do also appreciate the updated heart rate complication because it makes it so you don’t have to navigate to the full app on the watch at all if you just want to see your most recent pulse reading.

Activity and Workout apps

The watchOS 4 Activity app looks the same as before, but it now pushes more frequent and personalized alerts to you. One of the first new alerts I received was nearly immediately after I put on my watch for the day at 6:30am: “You rocked your exercise ring yesterday! Keep it going today.” That message included a brief summary of calories burned and minutes exercised from the previous day.

On those days where I hadn’t been as active as usual (typically lazy Sundays), I received another new notification that told me how many minutes I’d need to walk to close my move ring. I appreciate motivational alerts like the one I received first thing in the morning, but I like quantified alerts like this even better. Movement and exercise seem less like a chore when you know exactly how much you need to do to reach a goal. Some days might require longer post-dinner walks than others, but knowing you only need 10 more minutes of walking to complete a daily goal makes it easier to take that walk.

I haven’t spent a full month with watchOS 4, but Activity also pushes out new personalized monthly exercise challenges based on your previous month’s exercise logs. These won’t tell you what types of workouts to do, but, rather, they’ll push you to do a few more workouts that last longer during the current month. If you completed 10 workouts lasting about 20 minutes long each, the challenge might be to complete 11 workouts lasting 25 minutes each.

I like the idea of these monthly challenges—they tackle big-picture, long-term fitness goals, and they appeal to a wide variety of people because they’re not categorically specific. Apple uses your previous workout logs to inform the creation of these challenges, but it’s not going to tell you to run outside more rather than sticking to the elliptical. That’s both good and bad: it’s good because most people (those who are moderately active) will likely appreciate the slow increase these alerts suggest over time. However, it’s bad if you’re looking for more challenging or more specific workouts with which to change up your routine. This is where a guided workout routine library would come in handy (like the one available on the Fitbit Ionic). In the future, I hope watchOS 4 gets even smarter so it can at least offer a suggestion for how to switch up your workouts. For example, if 10 out of your 12 monthly workouts are indoor runs, your next monthly challenge might suggest taking your workout outdoors for the change in environment and terrain.

Let’s move on to the Workout app, which you may interact with more than the Activity app if you exercise regularly. This app has a new look and feel, with larger, gray bubbles that quick-start about 14 different exercises. The list will morph over time as you work out, moving your most frequently completed exercises to the top of the list so you can easily tap and go. The quick-start nature of these exercises is new: previously, only your most used workouts could be quick-started with a special bubble that saved your previous workout goal. Now, every bubble has a dot icon at the top-right corner that you tap to edit the goal for that specific session. I always have an open goal, but some may prefer setting a caloric-, time-, or distance-based goal.

The only new thing about the stats display during a workout is that the information has been bolded. Swiping to the right still brings up the control screen where you can pause or end the workout or lock the watch for water-based activities. There’s also now an “add” button on that page that lets you start a new exercise immediately without separately ending the exercise you’re currently completing. Tapping the “add” button lets you choose another exercise from the main Workout app, which then ends the previous exercise and begins the new one as soon as you tap it.

I love this multi-exercise feature, because I often start out doing strength training and then end a session with cardio. I don’t have to manually end my first session and start a new one whenever I want to move on. This comes in especially handy on my occasional all-cardio days when I hop from the stair-stepper to the elliptical to the treadmill to the stationary bike, all in an hour’s time.

The only thing I don’t like about the multi-exercise feature is that the group of exercises isn’t saved as a group. Rather, they are saved individually. If I use the “add” button to record strength training, treadmill, and HIIT (a new workout option in watchOS 4) sessions in succession, those three workouts will show up in the Activity app on the watch and in iOS as individual sessions. I’d like to see the stats from that exercise group as a whole: how many calories did I burn from those three workouts in total? What were my average and peak heart rates during that entire span of time? In the Activity app, you can see total exercise minutes and total active time, but grouped workout stats in addition to individual workout stats would be useful.

Swiping to the left from the main workout data page now brings up music controls so you can pause, play, and skip songs directly from the watch. It’s convenient to have music controls inside the Workout app, rather than being forced to go back to the app grid, find your music app, and control things from there. These controls work not only with Apple-controlled music but also with music from other sources like Spotify. It’s similar to the Now Playing complication in that it’s just an audio playback controller, so it’s not limited to Apple services or saved onboard music.

There’s one thing on the fitness side of watchOS that isn’t totally ready yet—GymKit. This allows the watch to pair with compatible gym equipment and share information with those machines. According to Apple, you’ll simply need to hold your watch up to the NFC reader on the treadmill, elliptical, or other machine. The watch will instantly pair with it, and then you’ll see stats, like heart rate, on the machine’s display. This will make it easier to view data during the workout, so you don’t have to lift your wrist every time you want to check your heart rate, pace, and other stats.

Once you end the workout, the watch should instantly unpair with the device so anyone else can use that machine immediately after you without being able to see your personal information. I’m bummed I couldn’t try this out, because it’s really convenient to use devices like the Polar H10 chest strap that automatically connect to compatible gym machines. Since many of those devices have been around much longer than the Apple Watch, they work with most gym machines. It will likely be a while before we can all connect our various Apple Watch models to GymKit-ready machines since equipment manufacturers either have to build the technology into new machines or update the firmware/software of existing equipment.

Heart rate app

Apple added a bunch of new metrics to the heart rate app in watchOS 4. Previously, it measured your heart rate whenever you entered the app and showed you the last recorded measurement. Now there are a number of new data fields: current heart rate, resting heart rate, walking average heart rate, the heart rates for each workout completed that day, and recovery heart rate. You can tap each bubble to see a graph of your heart rate relating to that topic over the course of the day. I’ve wished for these graphs since the Series 2 came out, so I’m happy to see watchOS 4 include them, especially directly on the watch.

You might be familiar with resting heart rate, but Apple calculates this measurement differently than other fitness trackers do. Resting heart rate is usually captured in the moments right after waking up, before getting out of bed. Many fitness trackers with heart rate monitors have incorporated this metric over the past few years for a few reasons: resting heart rate is a good indicator of overall health. Because a lot of these devices track sleep anyway, they can save heart rate data from right before and after you wake up, which can then be used to inform resting heart rate.

Since the Apple Watch doesn’t natively track sleep (nor does it have the battery life to do so for more than one night at a time), Apple measures resting heart rate differently. The Apple Watch takes heart rate readings from when it notices you haven’t moved in a while—like when you’re at your desk working—and uses a number of those readings to determine a resting heart rate estimate.

This method makes sense in theory: a number of pulse measurements taken when you’re presumably not doing much to exert the body could indicate your body’s base heart rate. However, there are a lot of things that influence heart rate: the timing of your last workout, caffeine, stress, or anxiety, just to name a few. So far, Apple’s resting heart rate calculation for me is slightly above what I know my resting heart rate to be from using other devices over months at a time. I’ve used a bevy of heart rate monitoring wristbands and chest straps for years, and I know my resting heart rate to be 59 BPM on average from that testing. My Series 2 watch often calculated my resting heart rate as 66 BPM—that’s not very far off, but it’s not as good as I know my body to be.

Walking heart rate is an interesting metric that I’ve only seen Apple attempt to track. Whenever you’re moving but not exercising (think grocery shopping, walking to your car, or doing other day-to-day things), the heart rate monitor records your pulse and translates it into walking heart rate. I didn’t see a walking heart rate reading until later in my day, likely because the Apple Watch needs to accumulate data from various walking periods before it can make an estimate. This figure basically tells you how hard your heart needs to work when your body is doing the most basic and less strenuous forms of exercise. However, I didn’t find myself constantly interested in what my walking heart rate was—I mostly focus on current, resting, and in-workout heart rates.

I’m happy to see the heart rate data from the day’s workouts included in the heart rate app, because you can’t separate workouts from the rest of your day. Your heart’s work during those strenuous times factors in to how it performs the rest of the day, so it’s convenient to be able to look back on just your exercise heart rate graphs in the heart rate app.

The final new pulse metric available has to do with exercise heart rate: now watchOS 4 records your recovery time, showing how quickly it took your heart rate to come down after exercising. While this graph doesn’t show how long it takes your heart rate to return to your recorded resting heart rate after exercise, it does show you how many minutes it took for your heart rate to lower by a couple beats per minute. This graph will be a great resource for anyone trying to improve their overall fitness, because it is proven that people with shorter recovery times (otherwise known as those who have a better cardiovascular condition) are at a lower risk for multiple health problems.

One last heart rate improvement in watchOS 4 isn’t included in the heart rate app on the watch. In the heart rate app settings in the Apple Watch app on iOS, you can turn on and edit an elevated heart rate warning. This feature lets the watch alert you if your heart rate is very high even though you’ve been inactive for more than 10 minutes. Depending on your fitness level, you may want to adjust the threshold for these alerts—I set my watch to alert me when my heart rate levels off at 100 BPM. This is a precautionary feature that could help those with heart conditions or health issues that affect heart rate detect problems before they start. I’m not at a higher risk for heart attack, nor do I have any major heart problems. However, I like having this feature on watchOS 4 to detect high levels of anxiety or nervousness. Typically I know when I’m stressed out, but getting a nudge on my wrist with a scarily high number representing my heart rate may encourage me to take a deep breath and relax.

New Music and News apps, plus other bits

The Music app has a new look in watchOS 4 with colorful album art showing off playlist artists. When the watch is charging, it will automatically sync and update music in the My New Music, My Favorites, My Chill Mix, and Heavy Rotation playlists. You can still choose other playlists to download to the watch at any time, and those will update while the watch charges as well. There are controls to shuffle all tracks or see your entire music library directly on the watch’s display.

Music also automatically syncs with AirPods, and they’re the first option that pops up when you choose a track to play and need to pick an audio output device. I had a pair of PowerBeats 3 earbuds lying around, which have the same W1 chip as the AirPods do, and those also appeared immediately in the list of available earbuds.

The Apple News app on the watch now shows you four stories relevant to the interests and followed outlets you set in the News app on iOS. It shows short descriptions of each story, allowing you to “save for later” to read in the iOS News app or to move on to the next story. You can’t read full articles on the watch, but who would want to anyway? The display is much too small for that.

In my preferred news apps, all I expect to see is a headline, a short description of the story, and maybe a photo. Now, Apple News delivers all three of those things in its alerts pushed to the watch. You’ll see the headline of the story along with its outlet of origin, a photo where possible, and a couple of sentences about the piece. Alerts have the same “save for later” option in addition to the “dismiss” button that all notifications have as well.

WatchOS 4 also brings Core Bluetooth capabilities to the Apple Watch, meaning compatible devices and apps can talk directly to the watch. Things like glucose monitors and specialized sport sensors can relay information to be displayed on the screen. So while this doesn’t turn your watch into a glucose monitor or any other Core Bluetooth device, it does allow the information collected by those devices to be shown on your wrist almost immediately.

Like GymKit on the fitness side, peer-to-peer Apple Pay on the watch isn’t ready yet either. This feature will roll out in a software update this fall, allowing Apple Watch users to pay each other through the Messages app. Any transaction will require biometric authentication, and money will be sent to the receiver as an Apple Pay cash card that works like a credit or debit card.

Continuous improvement

While watchOS 4 doesn’t fundamentally change the Apple Watch experience, it does upgrade it both in fitness and smartwatch aspects. Not surprisingly, many of the biggest updates are in the fitness and health space, and those updates were necessary. In order to compete with the other fitness devices around the $300 level, Apple needed to expand the heart rate capabilities of the watch in addition to making the exercise tracking experience better. Both of those goals are achieved in watchOS 4.

Could it be even better still? Absolutely. The Activity app isn’t as barren anymore thanks to new heart rate graphs and data, but it’s still not the most comprehensive. I’m happy that Apple included so much visible heart rate data on the watch itself, because that makes it easier to assess progress immediately after a workout or at the end of the day, no iPhone necessary.

The smartwatch improvements are good as well, particularly because they make the watch smarter without challenging how most of us use the device regularly. If you’re not a Series 3 owner, you’re still going to need your iPhone to do a number of things the watch cannot do. WatchOS 4’s updates, like the Siri watch face, the revamped Music app, and the new News app make on-watch interactions easier, but they don’t necessarily force you to do more on a tiny display than you’re comfortable doing.

I am disappointed that GymKit and peer-to-peer payments aren’t ready yet. Admittedly, I’d use GymKit more than peer-to-peer Message payments, but both are practical features that I wish I could have tested. I’m eager to see how seamlessly the watch connects and disconnects from a GymKit-compatible treadmill and how quickly I can pay my friend back for dinner without whipping out my iPhone.

I do worry about compatibility and ease of use in the future. WatchOS 4 can be downloaded by all Apple Watch models, including first-generation (often called Series 0) and Series 1 devices. However, it is known that first-generation models cannot do two things that newer Apple Watches can: automatically start a synced playlist when you start a workout and calculate resting heart rate. Those two features are only available on Series 1 and newer watches, so we’re already starting to see the phasing out of support for a device that was released fewer than three years ago.

Since I reviewed watchOS 4 on a Series 2 Watch, I also wonder how well the update performs on first-generation and Series 1 devices. I’ve seen a slowdown in my Series 2 since updating—nothing major, but there is a noticeable half-second lag when opening an app, returning to the watch face from the app grid, and in other similar transitions. That sluggishness hasn’t frustrated me enough to want an entirely new watch, but I expect those using first-generation devices may not be able to comfortably update much more after watchOS 4.

The Good

  • Available for all Apple Watch models.
  • Toy Story watch face animations are adorable.
  • Siri watch face gives the virtual assistant an interface and more of a personal assistant.
  • New feature lets you make a watch face out of any Photos image.
  • New in-workout music controls.
  • Lots of new heart rate metrics, including resting heart rate and recovery time.

The Bad

  • Siri watch face only pulls data from native Apple apps.
  • No guided workouts.
  • Multi-exercise workout option doesn’t group exercises together in the Activity app.
  • Resting heart rate calculation isn’t totally accurate.
  • GymKit and peer-to-peer Apple Pay not ready yet; coming this fall.

The Ugly

  • A couple watchOS 4 features aren’t available on first-generation watches, which raises questions about how much longer it will be supported in future watchOS updates.