Apple Health for Serious Lifters

Anvil Workout saves each finished workout to Apple Health as a Traditional Strength Training session, and reads back the calories and heart rate your Apple Watch recorded during it. You log the sets on your iPhone or your wrist, and your data stays on your devices.

What gets written to Apple Health

When you finish a workout, Anvil Workout writes one Traditional Strength Training workout to Apple Health, marked as indoor, with the time it started and the time it ended. It shows up in the Health app alongside your runs, rides and any other logged activity, and any app you let read your workouts, such as a nutrition app or a coach's dashboard, sees it like any other workout.

That workout carries its type and its times, and nothing more. Anvil adds no calories or heart rate of its own, so the ones in Health are what your Apple Watch, or another device, recorded. Your sets, reps and weights aren't sent to Health at all. They stay in Anvil, with the records and Stats worked out from them.

Where each number lives

What	Where it lives
The workout, with its type, start and end	Apple Health, written by Anvil when you finish.
Sets, reps, weight, RPE and set types	Anvil only. None of it goes to Health.
Personal records, estimated 1RM and volume	Anvil only, worked out on your device from your sets.
Active calories	Recorded in Health, usually by your Apple Watch. Anvil shows the total for the workout's time in your history.
Heart rate	Recorded in Health, usually by your Apple Watch. Anvil shows the average of the readings taken during the workout.
Workouts from other apps	They stay in Health. Anvil doesn't bring them into its history.

What gets read from Apple Health

During a workout, if your Apple Watch is logging heart rate and active energy for the same time window, Anvil Workout can surface those metrics on your session summary:

• Active energy burned (calories) during the workout
• Average heart rate across the session

Both numbers are pulled from Apple Health after the workout ends, and only for the exact time window of your session. They appear in your Anvil Workout history view next to the workout you completed.

How Apple Watch fits in

Anvil Workout includes a watchOS companion app that follows the workout running on your iPhone. You can mark a set done or skip it from your wrist, so you don't have to keep picking up your phone. When rest starts, the Watch counts it down in a ring and taps your wrist when it ends while the app is on screen. watchOS pauses an app when you lower your wrist, so a tap can be missed then.

Practical setup:

1. Start the workout on your iPhone, then open Anvil on your Watch. It shows the set you're on, and during rest, the one coming next.
2. Log sets from either device. A set marked done on one shows on the other, with no internet in between.
3. While you lift, your Apple Watch records heart rate and active energy on its own. Anvil's Watch app doesn't start a workout on the Watch, so the heart rate readings are less frequent than in a workout started in Apple's Workout app.
4. When you finish on your iPhone, Anvil saves the workout to Health and reads back the heart rate and calories recorded during it.

If you don't wear a Watch, Anvil Workout still saves the workout. Heart rate and calories just won't appear on that session.

Privacy and permissions

Apple's HealthKit is one of the strictest privacy frameworks on iOS. We think that's a good thing.

• When you first allow it (as you set the app up, under Apple Health in Settings, or at your first workout if you skipped both), iOS shows Apple's own permission dialog listing exactly what Anvil Workout wants to read and write. You approve each category individually.
• You can change permissions any time in Apple's Health app → your profile → Privacy → Apps and Services.
• If you revoke write permission, Anvil Workout stops saving workouts to Health. If you revoke read permission, we can't show calories and heart rate on session summaries.
• Anvil Workout never transmits Health data off your device. Apple's framework handles all access on-device; we simply ask for the data and display it.

Why it's built this way

Anvil Workout was built around HealthKit from the start. It's a local-first app, and Apple Health is where the rest of your training already lives on your devices, so a lifting session belongs there with your runs and rides.

What Anvil Workout doesn't do (yet)

We're honest about the gaps:

• No standalone Apple Watch tracking (without phone). The Watch app operates as a companion view for the workout running on your iPhone; it does not record standalone sessions without your phone nearby.
• No HealthKit history read. We don't read past workouts from Health and pull them into Anvil Workout's history. Our history view only shows sessions you logged with us directly.
• No body weight or body measurements. Anvil Workout focuses on lifting performance. If you track weight in the Health app, it stays there.