In TestFlight beta for iPhone and Apple Watch
Your next set, planned from what you lifted and how you slept.
VolumeArc is a strength training log with a coach built in. It reads your recovery data from Apple Health and suggests the weight and reps for each set. After a set, tap up, hold or down on your watch and the plan adjusts.
Not on the App Store yet. We’re testing with a small group first.
How it works
You lift. VolumeArc keeps the log, watches your recovery and sets up the next session.
- Log it on your wrist
- The Apple Watch app runs a full workout session with a rest timer and set logging. After each set, tap up, hold or down and the next set adjusts. If your phone is out of range, the watch keeps going and syncs your sets when it reconnects. On Apple Watch Ultra, the Action Button starts the workout and logs the next set.
- Recovery goes into the plan
- VolumeArc scores your readiness from Apple Health: your 7-day HRV against your 28-day baseline, sleep debt, the strength work you did this week, and wrist temperature and respiratory rate when your watch records them. On a low day the coach suggests lighter work or a deload instead of your usual numbers.
- Ask the coach
- Ask why today is light, what to swap for a machine that’s taken, or how to plan next week. On iPhones with Apple Intelligence, it answers on the device with Apple’s model when it can. Otherwise it goes to our cloud coach, built on Anthropic’s Claude. With no connection and no on-device model, it tells you it can’t answer right now instead of guessing.
- Limits it will not cross
- Weights the coach suggests are capped against what you’ve actually lifted, so it won’t jump your squat far past anything you’ve done. If you mention pain, it tells you to back off. If you describe something that sounds like a medical problem, it tells you to get it checked instead of programming around it.
On your iPhone, too
During a workout, the current set and rest countdown sit on the Lock Screen and in the Dynamic Island. Home Screen widgets show your next session.
You can send a planned session to Apple’s Workout app on your watch. Your training history syncs through your own iCloud account.
Bench press
Romanian deadlift
Overhead press
Free and Pro
Pro will cost $9.99 a month or $59.99 a year through the App Store. Purchases in the TestFlight beta don’t charge you.
Free
The whole training app.
- Workout log, rest timer and the Apple Watch app
- Readiness from Apple Health
- The full AI coach: Apple Intelligence where your iPhone supports it, and Anthropic’s Claude in the cloud
- iCloud sync, Live Activities and widgets
Pro
Form check.
- Form check: record a set and get feedback on your form
- The coach itself is the same as on Free
Questions
- When can I download it?
- VolumeArc is in a TestFlight beta. It goes on the App Store when testing is done, and we don’t have a date yet. If you want to try it now, ask for an invite.
- What do I need?
- An iPhone on iOS 27 or later. The watch app needs an Apple Watch on watchOS 27 or later. You can train without a watch, but most of the recovery data VolumeArc uses comes from one.
- Does it work without a signal?
- Logging does. The coach falls back to Apple’s on-device model where your iPhone supports it. Where it doesn’t, the coach tells you it’s unavailable instead of guessing. A question asked on the watch with no phone nearby waits until the phone is back.
- What leaves my phone?
- Your training history syncs through your iCloud account. When a question goes to the cloud coach, the app sends the question plus a summary of your recent training and recovery, such as “HRV down 8% this week”, not your raw Health data. The Privacy Policy lists every service involved.
- How do you know the coach gives good advice?
- We run it against a fixed set of test cases before releases: low and high readiness, injuries, requests for unsafe loads and attempts to talk it out of its rules. The latest results are public.
- Is this medical advice?
- No. VolumeArc plans training. It isn’t a doctor or a physical therapist, and it will tell you to see one when something you describe needs it.
- Will there be an Android version?
- No. We’re building for iPhone and Apple Watch only.