Working Out Offline | Client guide

How it works

EvoFit Trainer is a Progressive Web App with offline support:

The Service Worker caches the app shell + your most recent data on every load.
When you go offline mid-workout, set logs are written to IndexedDB locally.
When the device comes back online, a SyncManager flushes pending writes to the server.

You should never lose a set log because of bad signal.

What you see

An OfflineBanner appears at the top of the screen when you go offline.
A SyncStatus indicator shows pending sync count (e.g. "3 sets waiting to sync").
Once back online, the indicator turns green and shows "Synced".

What works offline

Action	Works offline?
Read today's workout (if visited online recently)	Yes
Log sets	Yes — queued in IndexedDB
Mark workout complete	Yes — queued
Substitute exercise	Partial — alternatives need network
Log a meal	Yes — queued
Log a measurement	Yes — queued
View exercise library	Cached only — full library needs network

What doesn't work offline

New programs / new check-ins (push from server requires network).
WhatsApp button (opens external app).
Push notifications.

Conflict resolution

If you log a set offline and your trainer edits the same workout template online before you sync, the system uses last-write-wins with a server-side timestamp tie-breaker. Conflicts are rare in practice (trainers rarely edit a workout you're mid-way through).

Step-by-step

Walk into the gym basement (no signal).
Open EvoFit. The cached app loads.
Start your workout. Log sets normally. The OfflineBanner shows.
After the workout, walk back outside. SyncStatus turns green.
Open the app — your trainer can now see the session.

Common pitfalls

Where to find this

Component: OfflineBanner, SyncStatus, OfflineIndicator.
Storage: IndexedDB with fake-indexeddb for tests.
Sync: lib/offline/sync-manager.ts with exponential backoff.