Getting started
1
You only need to do this once. After the initial connection the app stores your credentials securely on your device.
- Open the FluidLoss Companion app.
- Tap Analyse Past Activities.
- If Strava isn't connected yet, tap Connect Strava in the dialog that appears.
- You'll be taken to Strava's authorisation page. Grant access and return to the app.
- You should see: ✅ "Strava connected successfully!"
The app requests activity:read_all scope — it reads your activity data to run the analysis. It does not write to Strava or post anything on your behalf.
2
Share an activity from Strava
Once connected, use Strava's native share function to send an activity to FluidLoss:
- Open the Strava app on your phone.
- Find the activity you want to analyse.
- Tap the share icon (arrow pointing up/right).
- Select FluidLoss Companion from the share sheet.
The app will open automatically and begin fetching your activity data.
How the analysis works
3
Two-phase analysis runs automatically
Once you share the activity, everything happens in the background:
Phase 1
Fetching data
- Distance, duration, elevation
- Heart rate stream (sample-by-sample)
- Power and cadence data
- Velocity and altitude at each second
Phase 2
Calculating fluid loss
- Identifies sport type: cycling or running, road, mountain, virtual, treadmill
- Looks up temperature at your activity's location and time
- Pulls your physiology from your Garmin profile: max HR, VO₂ Max, weight
- Divides the activity into 30 equal time intervals
- Sends each checkpoint to the ML model and builds the full fluid loss curve
Results and saving
4
Review your results
When analysis completes, the Activity Recap screen appears showing:
- Activity profile: sport type, temperature, duration, distance
- Final fluid loss prediction in litres
- Fluid loss chart — how loss accumulated over the activity, showing exactly when you were losing fluid fastest
5
Save your results
At the bottom of the recap screen you have three options:
💾 Save
Stores the analysis. Review it anytime under Saved Predictions.
🗑 Discard
Closes the recap without saving.
✕ Close
Same as Discard — closes without saving.
Ready to get started?
Download the app and connect your Strava account to analyse your first activity.