An Apple Watch workout tracker built for the barbell

What can you do from the wrist?

• Log a set with one tap. The weight and reps are prefilled from your last working set, so most sets are a single press of “Log set”. A haptic confirms it.
• Change weight and reps with the Digital Crown. Tap the value you want to edit, turn the crown, done. The crown moves in 0.5 kg (1 lb) steps; the ± buttons jump by your equipment step: 2.5 kg on a barbell, 0.5 kg on dumbbells, 5 kg on a machine stack.
• See the exercise. Swipe to the movement page for a looping video of the exercise, straight from the watch. Reduce Motion shows a still frame instead.
• Rest with a countdown on your wrist. The timer starts when you log a set, clicks through the last seconds and taps you twice when time is up, so you feel it under a sleeve. Extend, shorten or skip the rest from the ring.
• Undo a wrong tap. A banner offers “Undo” for five seconds after every logged set, and a tap on the rest ring opens the same option with the set shown for confirmation.
• Warm-up sets on the watch. Ramp-up sets generated on iPhone show up on the wrist, marked as warm-ups.

Heart rate and Apple Health

Every workout started on the watch runs as a real workout session in watchOS. That gives you live heart rate and active calories on the rest screen, keeps the timer and haptics alive in the background, and saves a strength-training workout to Apple Health with your heart-rate samples and energy when you finish. The Health entry carries the workout name, such as “Workout A”, not just the app name.

If the process is killed mid-session, the watch reconnects to the live workout session when you reopen Alzo, and your logged sets are restored from disk.

Does Alzo on Apple Watch work without the iPhone?

Mostly yes, with one honest caveat. Alzo for Apple Watch is a companion app: your plans are built on iPhone and sent to the watch over WatchConnectivity. The first time, open Alzo on the iPhone so the plans transfer. From then on the catalog is cached on the watch.

During the workout the phone can stay in the locker or at home. The session, the timer, the heart-rate readings and every logged set live on the watch. When you finish, the result is written to the watch’s storage and sent to the iPhone; it stays on the watch until the iPhone confirms it saved the workout, so a phone that is off or out of range never loses a session. The next time both devices meet, the log catches up.

What still needs the iPhone: creating or editing plans, the coach’s analysis, charts and reports. The watch is for training, the phone is for planning and reviewing.

Live sync between iPhone and Apple Watch

Start a workout on iPhone and the watch picks it up live, with the same weights, the same set cursor and the same rest timer. Start on the watch and the phone mirrors it. Log a set on either device and the other one updates, with a haptic on the watch when progress arrives from the phone. Only one device saves the workout to Apple Health, so there are no duplicates.

Voice cues can play from the iPhone in your locker while you train from the watch, or from the watch itself through its speaker or your AirPods. On the watch the voice is off by default; switch it on in the Watch app settings.

Always-On display and the coach

With the wrist down, the set screen stays readable in Always-On mode with the accent dimmed, and taps are ignored so a brushed sleeve does not log a set: the first tap only wakes the display. The rest ring shows the remaining time in Always-On as well.

The coach lives on the iPhone, but its decision reaches the wrist. In Alzo Pro, when the log says you are ready to add weight, the watch shows the proposed heavier weight as a chip on the set screen; one tap accepts it for that set. In the free version the proposal stays on the phone and the watch simply prefills your last working weight.

Requirements

Alzo needs iOS 18 or later on iPhone and watchOS 11 or later on Apple Watch. The Watch app is included with the iPhone app and requires Alzo on the iPhone to receive plans. Heart rate and Health saving need your permission in the Health app, asked once on the watch.