Strong's speed reputation is earned.
Strong has spent years owning the serious, quiet logging lane. Callus is not trying to bury that; it is matching that calm and adding a deeper training brain.
Switch from Strong
Strong's speed, plus the brain Strong never built.
Strong nailed the notebook replacement. Callus keeps the fast, quiet logger, then adds dominance PRs, no-account startup, deload-aware coaching, fatigue signals, and relative strength.
No cheap shots
Strong is still the speed benchmark.
The Watch pedigree is real.
Strong has long shipped Apple Watch support and still advertises phone-free workout logging. Callus should be judged against that bar.
This is maintenance versus momentum.
Strong is not a dead app. The difference Callus is arguing for is the intelligence layer: PR logic, readiness, deloads, fatigue, and relative strength.
Comparison table
Where Callus is different.
| Point | Callus | Strong | Source |
|---|---|---|---|
| Logging speed | Fast set entry, instant confirmation, no save button, and a complete offline path for the core logger. | Strong publicly positions itself as simple, intuitive, and designed to record workouts quickly without extra distractions. | Strong App Store listing Checked June 12, 2026 |
| Account contrast | Callus starts with Continue offline. An account is only for optional sync and social features. | Strong now leads its public site with Get Started and Strong Accounts are Free Forever, alongside Cloud Sync positioning. | Strong official site Checked June 12, 2026 |
| Free limits | The free tracker includes unlimited logging, all 10 set types, the PR engine, import/export, and five templates. | Strong says the free version can save unlimited workouts, but is limited to 3 custom routines. | Strong App Store listing Checked June 12, 2026 |
| Coach's eye | Deload prescriptions, readiness and fatigue signals, plateau forecasts, overload suggestions, and DOTS-aware relative scoring. | Strong lists advanced statistics, PRs, 1RM, total weight lifted, body measurements, and volume/1RM graphs; it does not publish deload, fatigue, plateau, or DOTS coaching on its App Store listing. | Strong App Store listing Checked June 12, 2026 |
| Watch | Apple Watch is a fast companion for logging and PR feedback; the phone remains the full planning and review surface. | Strong has a fully featured Apple Watch app and says workouts can be logged with or without the iPhone. | Strong App Store listing Checked June 12, 2026 |
Import walkthrough
Keep the notebook. Upgrade the math.
The import is a bridge, not a ceremony. Bring the old sessions in, review the defaults, then let Callus re-score the library.
- Export your Strong workout history as CSV.
- Open Callus, go to Settings, then Import Data, and choose the Strong CSV.
- Confirm the default unit and review imported exercise classifications, because Strong exports do not carry every Callus field.
- Callus stores the imported sets as working sets, then recomputes PRs across the full library.
Sources
Sources for Strong claims
Facts checked June 12, 2026. Competitor claims above cite the public sources below.
- Strong official site Account, Cloud Sync, user-count, Watch, and product-positioning claims.
- Strong App Store listing Feature list, Apple Watch support, free routine cap, pricing, and App Store rating.
Callus is pre-launch
Join before you migrate.
Callus is in final App Store testing. The waitlist gets the first invites and the first importer fixes if a Strong export format changes.