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HYROX on Apple Watch: why a native workout cannot split the 16 segments, and what a pacer app can do

For HYROX athletes who race with an Apple Watch · Updated 2026-09-12 · Sources: Apple Developer Documentation (WorkoutKit, HealthKit), Apple Support and Newsroom, HYROX Singles Rulebook 26/27

The Workout app on Apple Watch records a HYROX race as one activity, because every tool Apple offers for splitting a workout either excludes this case or is only available to a third-party app. Custom Workouts are not available for the Multisport type, Multisport is defined as swimming, cycling and running, and the API that partitions a workout into activities, HKWorkoutActivity, has to be called by an app. Below: Apple's documentation, what a pacer app can and cannot do, per-station targets, and battery and Water Lock from Apple Support.

The short answer

Apple's guide states that Custom Workouts are available in all workout types except Multisport and Open Water Swim. You can build 16 timed steps in one sport, not a run-then-station sequence.
Multisport, added in watchOS 9, "automatically switches between any sequence of swimming, biking, and running workouts, using motion sensors". A sled push is none of those.
The split you want exists in HealthKit as HKWorkoutActivity (iOS 16, watchOS 9), which "partition[s] a workout into a set of separate activities". Only an app can create those activities during a session.
Battery: Apple lists up to 10 hours of workout tracking on Series 12, 7 hours on SE 3 and 45 hours in Max Extended Workout mode on Ultra 4. A 90-minute race is not the problem; the 4 hours around it are.

Availability figures are Apple's: WorkoutKit requires iOS 17 and watchOS 10. Everything is as documented on 2026-09-12.

What Apple's Workout app can and cannot split

Apple Support's list of workout types runs to 80-odd entries, including Running, Rowing, Functional Strength Training, High Intensity Interval Training, Cross Training, Mixed Cardio, Multisport and Other, which Apple says to use "when you can't find a matching workout type". There is no hybrid-race type; whichever you choose is recorded as a single workout with one set of metrics.

The native tool for structure is the Custom Workout: "You can tailor your workouts to include a warmup period, repeating work and recovery intervals, and a time to cool down." Each interval is set by time, distance or open, with alerts. The same page carries the restriction that matters: "Custom Workouts are available in all workout types, except Multisport and Open Water Swim." You could build an Outdoor Run with 16 open-ended steps and advance them by hand, but the watch would show run metrics for the whole race, sled included.

Multisport is the type that changes sport mid-workout, and Apple's watchOS 9 announcement defines its scope: "The Workout app now supports a new Multisport workout type that automatically switches between any sequence of swimming, biking, and running workouts, using motion sensors to recognize movement patterns." The developer documentation says the same in API terms: swimBikeRun is "the constant for multisport activities like triathlons", and the transition type "represents the transition between sports in a swimBikeRun workout". Nothing in HYROX is a swim or a bike, so the switching has nothing to detect.

Apple feature	What it does (Apple's wording)	Why it does not split HYROX
Custom Workout	Warmup, repeating work and recovery intervals, cooldown; time, distance or open goals; alerts	One sport per workout; excluded for Multisport
Multisport	Automatically switches between swimming, biking and running using motion sensors	No station resembles swim or bike
Pacer	Choose a distance and goal time; the watch calculates the pace required	One distance, one pace; HYROX has 8 runs separated by stations
HKWorkoutActivity (API)	Partitions a workout into separate activities, e.g. the swim, bike and run of a triathlon, or active and rest periods	Does the job, but only an app calling HealthKit during the session can create the activities

Where the 16-segment split actually lives: HKWorkoutActivity

Apple's HealthKit documentation is explicit that a workout can be partitioned: "Workout activity objects partition a workout into a set of separate activities. For example, you can use workout activities to record the swim, bike, and running portions of a multisport event, like a triathlon, or to represent the active and rest periods during interval training." Every HKWorkout has at least one activity; if an app sets none, HealthKit assigns one matching the workout's type.

The companion article, Dividing a HealthKit workout into activities, describes the mechanism: "when an activity begins, create a new configuration for the activity, and start the activity using the session's beginNewActivity(configuration:date:metadata:) method". Ending one is endCurrentActivity(on:), and "HealthKit also ends the current activity when you begin a new activity." Activities "can't overlap, but they also don't need to cover the entire HKWorkout sample's duration."

Read against a HYROX race this fits well: a running activity for each 1 km, a functionalStrengthTraining or rowing activity for each station, optional transition activities for the Roxzone. The catch is in the same sentences: beginNewActivity is a method on a live session that an app owns, and the Workout app exposes no control that calls it. Apple's WorkoutKit framework, which hands app-designed workouts to the Workout app, offers SingleGoalWorkout, PacerWorkout, SwimBikeRunWorkout and CustomWorkout; none is a sequence of different sports with different metrics.

Summary of the documentation: the native Workout app gives you one activity, or a single-sport interval structure, or a swim-bike-run switcher. Sixteen separately timed segments of mixed running and stations require an app that runs its own session, or one that skips HealthKit and simply times segments on the wrist.

What a pacer app on the watch can and cannot do

Because the watch cannot tell a sled push from a farmers carry by motion, and indoor lap courses defeat GPS, every pacer app makes the same trade: the athlete tells the watch when a segment starts.

Can do:

Hold 16 targets built from your goal finish and division, and show the target for the current segment.
Show time remaining to that target, or time over it, updating each second.
Give one haptic when the target passes.
Record the actual lap for each segment as you tap, and show lap versus target for all 16 at the finish.
Run without the phone, which the 26/27 rulebook forbids on the floor; the plan must be synced and stored on the watch beforehand.

Cannot do:

Detect the start of a station or a run by itself. No documented Apple API classifies HYROX movements.
Replace the official timing chip. The rulebook requires the chip on an ankle at all times; your watch laps are for you, not the leaderboard.
Count your laps. The rulebook makes racers solely responsible for that; a pacer shows a target for Run 3, not which lap you are on.
Rescue an unrealistic plan. If the targets came from a finish time you cannot run, the watch will show "over" 16 times.

How to set per-station targets that survive contact with the race

The common mistake is dividing the goal time by 16. Runs and stations do not take equal time, and the runs slow as the race goes on. A usable plan follows this order.

Pick a goal from evidence: your last official result plus a realistic improvement, or a time trial of the run segments.
Distribute the time across the 16 segments using published division averages, not equal parts. Stronger runners shift time from the runs into the stations, and vice versa.
Add the Roxzone. Spreading transition time evenly across the 16 transitions is a reasonable default; a plan that ignores it shows "over" from Run 2 onward.
Convert the per-segment targets into cumulative times; that is the figure you glance at leaving each station.
Rehearse the tap in training: a 1 km run followed by a station, tapping at both changes.
Sync the plan to the watch the night before, open the pacer once to confirm it loaded, then charge.

Example: 1:30:00 goal, Men Open
Equal split: 90 min ÷ 16 = 5:37 per segment, a 5:37 SkiErg and a 5:37 Run 1, both wrong by minutes.
Distributed: eight runs that start faster and drift slower, eight stations with their own shares, Roxzone spread across transitions.
→ Carry the distributed plan.

Battery, Low Power Mode and Water Lock

Apple's battery page gives the current figures: Apple Watch Series 12 "Up to 10 hours workout tracking" and "Up to 24 hours" all-day; Apple Watch SE 3 "Up to 7 hours workout tracking" and "Up to 18 hours"; Apple Watch Ultra 4 "Up to 45 hours Max Extended Workout tracking" and "Over 2 days (up to 50 hours)". Each carries the caveat that "Battery life varies by use, cellular coverage, configuration, and many other factors; actual results will vary."

A 60-120 minute race is well inside those numbers. What drains the watch is the day: navigation, a long wait after check-in, and a session started early in the warm-up area. Start the pacer at the start line, not in the holding pen, and charge in the morning.

Low Power Mode is the fallback. Apple's battery page lists it separately ("Up to 38 hours in Low Power Mode" for Series 12), and Apple's Ultra announcement describes a further workout setting that "reduces frequency of GPS and heart rate readings". Indoors, fewer GPS readings cost nothing. Under 30% at check-in, turn it on and keep the pacer.

Water Lock is about sweat and chalk. Apple's water resistance page explains that Water Lock locks the screen "to avoid accidental taps", turns on automatically when you start a swimming workout, and for other workouts is enabled from Control Center. Turning it off means pressing and holding the Digital Crown, which plays "a series of tones" to clear water from the speaker. The trade-off: with Water Lock on, a sweaty forearm cannot trigger a tap, but neither can you tap the pacer at the next segment without holding the crown first. If your pacer needs a tap per segment, keep Water Lock off and wipe the wrist in the Roxzone.

The 26/27 Singles Rulebook lists permitted items (knee sleeves, gloves, belt, wristbands, hydration packs, inhalers, respiratory devices) and forbidden items (headphones, cell phones, body cameras, ear plugs, camera-equipped glasses). A wrist watch is on neither list, and the rulebook's default is that unlisted items are prohibited. Watches are widely worn at HYROX races; for certainty, ask the local customer support team before race day.

Frequently asked questions

Which workout type should I pick on Apple Watch for HYROX?

There is no HYROX type. Apple's list includes Running, Rowing, Functional Strength Training, High Intensity Interval Training, Cross Training, Mixed Cardio and Other. Apple's HealthKit documentation describes crossTraining as any mixture of cardio, strength and flexibility training, the closest description of a HYROX race. Whichever you choose, the native app records one activity and will not produce 16 splits.

Will my Apple Watch battery last a HYROX race?

For a 60-120 minute race, yes, if you start charged. Apple's battery page states up to 10 hours of workout tracking for Apple Watch Series 12, up to 7 hours for SE 3 and up to 45 hours in Max Extended Workout mode for Ultra 4, with the note that battery life varies by use and configuration. The risk is the day around the race, not the race. Charge to 100% the night before and top up before you leave the hotel.

Should I turn on Water Lock during HYROX?

Only if your pacer needs no taps. Apple's water resistance page says Water Lock locks the screen to avoid accidental taps, turns on automatically only for swimming workouts, and is otherwise enabled from Control Center; turning it off requires pressing and holding the Digital Crown. If your pacer needs a tap at each segment, leave Water Lock off and wipe the wrist in the Roxzone instead.

SIXTEEN: the 16-segment pacer on your wrist

SIXTEEN is built around that trade. On the iPhone you enter your division and goal time and it builds the 16 targets from published division averages, Roxzone included, with a cumulative column. The plan syncs to the Apple Watch and is stored there, so the race runs without the phone. On the wrist you see the current segment's target and time to target or over; you tap Next at the start of every segment, the watch gives one haptic when a target passes, and it lists lap versus target for all 16 at the finish. After the race, enter the official splits and the diagnosis shows where each segment sits among finishers in the same finish-time band, modelled from public statistics rather than raw results. Diagnosis and pacer are free; Pro adds a 6-week block for your two weakest stations. Japanese and English.

SIXTEEN

HYROX 16-station diagnosis and Apple Watch pacer. Japanese and English

Get SIXTEEN on the App Store

Unofficial tool. HYROX is a trademark of HYROX World GmbH, which is not affiliated with this site. Splits are computed on the device. A free web version of the diagnosis is at kanauworks.com/sixteen.

Related guides

HYROX Osaka race guide — INTEX Osaka stations, fares, January weather and the official check-in rules for 21-25 January 2027.
HYROX in Japan: 2027 race calendar — Osaka and Nagoya dates, Port Messe Nagoya access and the official check-in rules.

Sources

All checked on 2026-09-12.