The collection / MettleIn development

Mettle

Strength training for iPhone

Know what to lift next.

Mettle uses your logged sets to plan the next workout and shows why it chose each rep target and weight. Ask the coach to change an exercise or fit the session into the time you have.

Explore Mettle Check requirements

Programming and coaching run on your iPhone. Training records use private iCloud storage by default when available. Full boundary

iPhone · Apple Watch companion
In development. Not yet available to install.

Mettle: See the plan. App preview with example content. In development.
Inspect the training week, session details, and the plan’s “Why this?” control.App preview · Example content · In development

Your next sets and reps

See what changed since last time.

You hit the top of the rep range, missed a target, or came back after a break. Mettle uses that history to work out the next weight and tells you why.

  1. Log the work.

    Record the reps and weight you completed. Mettle looks at up to three recent sessions for each exercise when planning the next one.

  2. Get your next targets.

    Training rules decide when to add weight, aim for more reps, or back off. Those same rules record the reason for the change.

  3. See the reason.

    Open “Why this?” to see the training history and rule behind your targets. Ask the coach if you want to discuss a change.

Without previous sets to work from, Mettle starts with your goals, experience, equipment, and baseline information.

Make the session fit your day.

Tell the coach when you have less time or need a different exercise. Review the suggested changes to your exercises, session length, or training days before applying them.

Saved restrictions help later plans account for the same constraints.

Leave your phone between sets.

Use spoken cues and rest timers to follow the workout. The Apple Watch companion lets you log sets and control the active session on your iPhone from your wrist.

Rep detection supports selected movements. The Watch companion needs the active phone session.

Free and Pro

Start with a complete training plan.

In development

Planned features and limits are shown below. Pricing and compatibility will be confirmed before release.

Free

  • One active program, with past plans kept read-only
  • Coach conversations, athlete memory, and constraints
  • Watch logging and training-history import and export

Pro

  • Switch between saved programs
  • Weekly reviews, deeper trends, and block comparisons
  • Proactive form cues and expanded records

Planned: Free · Pro $4.99/mo · $29.99/yr · $79.99 lifetime

What you will need

The current build targets iPhone on iOS 26.1 or later with Apple Intelligence available. The workout remote requires watchOS 26. Training screens currently use pounds.

Bring your previous workouts.

Import set history from CSV, review the detected records, and choose the weight unit before saving. Undo an import if it is wrong. Export your history again without a paid plan.

CSV compatibility depends on the file’s columns. Check the preview to see which records Mettle can read.

The Boundary Check

How Mettle handles your records.

Where the work happens, where your records live, and which features use a connection.

Where does the processing happen?
Workout programming runs in local code. Apple Foundation Models provides on-device coaching and exercise selection from a curated shortlist.
Where does the storage live?
Training records use private iCloud storage by default when available, with a local fallback. This is the default storage choice, rather than an optional sync setting.
What connects to the network, and when?
Private iCloud, optional Health access, and the Watch companion use Apple services. Model setup and App Store purchases can also require a connection.
Read the collection’s privacy model

Before release

Questions about Mettle.

Open “Why this?” to see the training history and rule behind the change. For example, reaching the top of a rep range can lead to more weight next time. Mettle records that reason as it calculates your targets, so the explanation comes from the decision itself.