Complete User Guide

Getting Started

First Time Setup

  1. Download and Install: Install the FluidLoss Companion app from the App Store (iOS) or as a beta (Android).
  2. Install Garmin Data Field: Download and install the FluidLoss data field on your Garmin Edge bike computer from the Connect IQ store.
  3. Privacy Consent: When you first open the app, accept the privacy policy to continue.

Connecting Your Garmin Device

  1. Open the FluidLoss Companion app on your phone.
  2. Tap the "Connect to your Garmin Bike Computer" button on the main screen.
  3. Wait for the app to scan for nearby Garmin devices.
  4. Select your Garmin Edge device from the list.
  5. Wait for the connection to be verified. You'll see a confirmation message when the device is connected and the FluidLoss data field is detected.
  6. Once connected, you'll see your device name and a unique User ID displayed on the main screen.

Note: On Android, you may be asked to grant Bluetooth and Location permissions for device scanning. These are required to find and connect to your Garmin device.

Importing Activities from Garmin Connect

To train a personalized model, you need to import past activities from Garmin Connect and add your measured fluid loss for each one.

Method 1: Manual URL Entry

  1. Open Garmin Connect (website or app) and find the activity you want to import.
  2. Copy the activity URL. It should look like: https://connect.garmin.com/modern/activity/123456789
  3. In the FluidLoss app, tap "Import Activity" (or use the menu if available).
  4. Paste the URL into the text field.
  5. Tap "Import".
  6. The app will automatically extract activity data (distance, duration, heart rate, temperature, etc.).
  7. When prompted, enter your actual measured fluid loss in milliliters (mL) for that activity.
  8. Tap "Save" to store the activity.

Method 2: Share from Garmin Connect App

  1. Open the Garmin Connect app on your phone.
  2. Navigate to the activity you want to import.
  3. Use the share function (usually a share icon or button).
  4. Select "FluidLoss Companion" from the share options.
  5. A banner will appear at the top of the FluidLoss app main screen saying "Activity ready to import".
  6. Tap the "Import" button on the banner, or tap the "X" to dismiss it for later.
  7. The app will automatically extract activity data (distance, duration, heart rate, temperature, etc.).
  8. When prompted, enter your actual measured fluid loss in milliliters (mL) for that activity.
  9. Tap "Save" to store the activity.

Note: If you dismiss the banner, you can still access the import later through the "Personalised Model Training" → "Import Activity using this device" option.

What Gets Imported

The app extracts key activity data (distance, duration, heart rate, temperature, etc.) from your Garmin activity. You must manually enter your measured fluid loss for each activity. The most accurate way is to weigh yourself before and after your ride; the weight difference in grams equals milliliters of fluid lost.

Activity Identification

Activities are automatically identified by their Garmin activity ID. If you re-import the same activity, it will overwrite the previous entry rather than creating a duplicate.

Method 3: Web Import from PC/Mac

You can import activities from a web browser on your computer using QR code scanning.

  1. On the main screen, tap "Personalised Model Training".
  2. Tap "Import/Backup activities on PC/Mac".
  3. Open the FluidLoss web interface on your computer (https://fluidloss.info/).
  4. On the web page, initiate the import process to generate a QR code.
  5. Scan the QR code displayed on the web page using your phone's camera.
  6. The app will connect to the web session and automatically import activities as you add them on the web page.
  7. For each activity imported from the web, you'll be prompted to enter your measured fluid loss in milliliters (mL).
  8. Activities are automatically saved to your device as they are imported.

Note: The web import session remains active while you're on the "Saved Activities" screen. You can import multiple activities in one session.

Backing Up and Restoring Activities

You can backup your saved activities to a computer and restore them later. This is useful when switching devices or as a safety backup.

Backing Up Activities

  1. On the main screen, tap "Personalised Model Training".
  2. Tap "Import/Backup activities on PC/Mac".
  3. Open the FluidLoss web interface on your computer (https://fluidloss.info/).
  4. On the web page, initiate the backup process to generate a QR code.
  5. Scan the QR code displayed on the web page using your phone's camera.
  6. The app will connect to the web session and wait for the backup request.
  7. On the web page, confirm that you want to create a backup.
  8. The app will automatically upload your database file containing all saved activities.
  9. You'll see a confirmation message when the backup is complete.

What gets backed up: All saved activities with their metrics and fluid loss values are included in the backup.

Restoring Activities

  1. On the main screen, tap "Personalised Model Training".
  2. Tap "Restore Training Activities from PC/Mac".
  3. Open the FluidLoss web interface on your computer (https://fluidloss.info/).
  4. On the web page, initiate the restore process to generate a QR code.
  5. Scan the QR code displayed on the web page using your phone's camera.
  6. The app will connect to the web session and wait for the restore file.
  7. On the web page, select a backup file to restore and choose whether to restore predictions as well.
  8. The app will automatically download and restore the activities from the backup file.
  9. You'll see a confirmation message showing how many activities were restored.
  10. After restore, you'll be taken to the "Saved Activities" screen to view the restored activities.

Important: Restoring activities will replace your current saved activities with the ones from the backup. If you want to keep your current activities, make a backup first.

Restore options: When restoring, you can choose whether to also restore prediction history. Activities are always restored, but predictions are optional.

Managing Saved Activities

Tap "Saved Activities" on the main screen to view all imported activities.

Viewing Activities

Each activity card shows sport type, fluid loss, distance, and duration. Tap a card to open it in Garmin Connect (if available).

Deleting Activities

Delete a Single Activity

  1. Swipe left on the activity you want to delete.
  2. Confirm the deletion in the dialog that appears.

Delete Multiple Activities

  1. Tap the menu icon (⋮) in the top-right corner of the Saved Activities screen.
  2. Select "Select activities".
  3. Tap the checkboxes next to the activities you want to delete.
  4. Tap the delete icon (trash) in the top-right to delete all selected activities.
  5. Tap the close icon (X) to exit selection mode.

Delete All Activities

  1. Tap the menu icon (⋮) in the top-right corner.
  2. Select "Delete all".
  3. Confirm the deletion in the dialog.

Warning: Deleting activities cannot be undone. Make sure you want to delete before confirming.

Training Your Personalized Model

Requirements

To train a personalized model, you need:

  • At least 5 activities with measured fluid loss
  • Activities with varied conditions (different temperatures, durations, intensities) for best results
  • Accurate fluid loss measurements

Recommendation: For best accuracy, aim for 10+ activities across different conditions before training.

Training Process

  1. Import and save at least 5 activities with measured fluid loss (see Importing Activities).
  2. Go to "Saved Activities" to verify you have enough activities.
  3. If you have fewer than 5 activities, the "Train Cloud Model" button will be disabled and you'll see a warning message.
  4. Once you have 5 or more activities, tap "Train Cloud Model".
  5. The app will send your activity data to the cloud service for training.
  6. Training typically takes a few minutes. You can monitor progress on the server if you have access to logs.
  7. When training completes, your personalized model will be saved and ready to use for future predictions.

Training Modes

You can select a training mode that affects how the model is trained:

  • Training based on profile: Uses your activity profile to determine training type (default)
  • Training indoor: Optimizes for indoor/virtual activities
  • Training outdoor: Optimizes for outdoor/road activities

To change training mode:

  1. Tap the menu icon (⋮) in the top-right corner of the main screen.
  2. Select "Training Mode".
  3. Choose your preferred mode and confirm.

Note: Training mode only affects future training sessions. It doesn't change existing models.

Real-Time Tracking and Predictions

Starting a Tracking Session

  1. Make sure your Garmin device is connected (see Getting Started).
  2. Start an activity on your Garmin Edge bike computer (make sure the FluidLoss data field is active).
  3. In the FluidLoss app, tap "Start Tracking".
  4. The app will begin receiving metrics from your Garmin device.
  5. Predictions are calculated and sent to your Garmin device approximately every 2 minutes.

Auto-Start Feature

The app can automatically start tracking when it detects that an activity has begun on your Garmin device.

Enable/Disable Auto-Start

  1. Tap the menu icon (⋮) in the top-right corner.
  2. Select "Enable Auto-start" or "Disable Auto-start".
  3. The current status is displayed on the main screen below the model information.

How it works: When auto-start is enabled, the app monitors your Garmin device. As soon as it detects that activity time has started (time > 0), tracking automatically begins without you needing to tap "Start Tracking".

Viewing Real-Time Metrics

While tracking is active, the main screen shows predicted fluid loss (mL) and a scrollable grid of current metrics from your Garmin device. Predictions update approximately every 2 minutes.

Stopping Tracking

  1. Tap "Stop Tracking" on the main screen.
  2. The app will stop receiving metrics and sending predictions to your device.
  3. A Session Recap popup will automatically appear showing a summary of your activity.

Session Recap Popup

When you stop tracking, a recap dialog appears with a fluid loss chart and key stats (duration, distance, aerobic TE, final predicted fluid loss).

Recap Options:

  • Save: Saves the prediction to your history. You can view it later in "Saved Predictions".
  • Discard: Closes the recap without saving. The prediction will not be stored.
  • Close (X): Same as Discard - closes without saving.

Note: If you close the recap without saving, the prediction is automatically discarded. Metrics will remain displayed on the main screen until the next tracking session or until the app is closed.

Viewing on Your Garmin Device

The latest fluid loss prediction is automatically sent to your Garmin Edge bike computer and displayed on the FluidLoss data field. This updates approximately every 2 minutes during active tracking.

Model Settings and Preferences

Accessing Model Settings

  1. Make sure your Garmin device is connected and verified.
  2. Tap the menu icon (⋮) in the top-right corner.
  3. Select "Model Settings".

Model Preference Options

You can choose which model to use for predictions:

Personalised (Always Recommended)

Uses your trained personalized model if available. If no personalized model exists, falls back to the generic high sweater model.

Requirements: A trained personalized model.

Auto

Automatically uses your personalized model if available, otherwise uses the generic high sweater model.

Generic Models

Three generic model options are available:

  • Generic (low sweater): Predictions are 1/3 of the standard generic model
  • Generic (medium sweater): Predictions are 2/3 of the standard generic model
  • Generic (high sweater): Full generic model predictions (default)

Changing Model Preference

  1. Open Model Settings (see above).
  2. Select your preferred model option using the radio buttons.
  3. The change takes effect immediately for future predictions.
  4. The current model status is displayed on the main screen.

Model Status Display

The main screen shows your current model status, such as:

  • "Using Personalised Model"
  • "Using Generic Model (Low Sweater)"
  • "No Personalised Model (using Generic High)"
  • "Auto Mode (using Personalised)"
  • "Training Personalised Model (using Generic High)"

This helps you understand which model is currently being used for predictions.

App Settings and Preferences

Accessing the Menu

Tap the menu icon (⋮) in the top-right corner of the main screen to access all settings and options.

Available Menu Options

How to Use

Opens an in-app guide with basic usage instructions and tips.

Model Settings

Configure which model to use for predictions (see Model Settings). Only available when device is connected.

Training Mode

Select the training environment preference for future model training (indoor, outdoor, or profile-based).

Enable/Disable Auto-start

Toggle automatic tracking when activity is detected on your Garmin device (see Real-Time Tracking).

Light Mode / Dark Mode

Switch between light and dark themes for the app interface.

Quit App

Closes the application completely.

Version Information

Displays the current app version.

Saved Predictions

Tap "Saved Predictions" on the main screen to view a history of predictions made during past tracking sessions.

Viewing Saved Predictions

Each card shows date/time, fluid loss, distance, and duration. Tap a card to open the same recap view (chart + key stats) that appears after stopping a tracking session.

Managing Saved Predictions

Delete a Single Prediction

  1. Swipe left on the prediction you want to delete.
  2. Confirm the deletion in the dialog that appears.

Delete All Predictions

  1. Tap the menu icon (⋮) in the top-right corner of the Saved Predictions screen.
  2. Select "Delete All".
  3. Confirm the deletion in the dialog.

Personalised Model Training

Tap "Personalised Model Training" on the main screen to access advanced training options.

Available Options

From the Personalised Model Training screen, you can:

  • Import Activity using this device: Import a single activity by entering a Garmin Connect URL directly on your phone (same as the main "Import Activity" feature).
  • Import/Backup activities on PC/Mac: Use QR code scanning to import activities from or backup activities to a web browser on your computer (see Backing Up and Restoring Activities).
  • Restore Training Activities from PC/Mac: Use QR code scanning to restore previously backed up activities from your computer (see Backing Up and Restoring Activities).
  • View Saved Activities: Opens the "Saved Activities" screen to view and manage all imported activities.

This screen provides additional tools for managing and training your personalized model beyond the basic training available in the "Saved Activities" screen.

Android: Keeping the App Running in Background

Android devices sometimes pause apps to save battery, which can interrupt tracking during rides. To ensure FluidLoss continues tracking throughout your entire ride, you need to configure your device's battery settings.

General Steps (Most Android Devices)

  1. Allow Background Activity:
    • Go to Settings → Apps → FluidLoss → Battery
    • Choose "Unrestricted", "No restrictions", or "Allow background activity"
  2. Disable App Pausing:
    • Go to Settings → Apps → FluidLoss
    • Turn OFF "Pause app activity if unused" or "Unused apps"

Brand-Specific Instructions

Samsung

  • Battery and device care → Battery → Background usage limits: Remove FluidLoss from sleeping apps
  • App power management: Set FluidLoss to "Unrestricted"

Google Pixel

  • Apps → FluidLoss → Battery: Select "Unrestricted"
  • Apps → Special app access → Unused apps: Turn OFF for FluidLoss

OnePlus / Oppo / Realme

  • Battery → App battery management or Battery optimization
  • Find FluidLoss and select "Don't optimize" or "Allow"

Xiaomi / MIUI

  • Battery → App battery saver → FluidLoss: Select "No restrictions"
  • Security app → Autostart: Enable FluidLoss

Finding Settings

If you can't find these options, use your device's Settings search function and search for:

  • "Battery"
  • "Background activity"
  • "Unused apps"
  • "App optimization"

Note: You only need to configure this once. The settings will persist until you change them.

Tips and Best Practices

For Best Prediction Accuracy

  • Import varied activities: Include rides with different temperatures, durations, and intensity levels.
  • Accurate measurements: Measure fluid loss accurately by weighing yourself before and after rides. The weight difference in grams equals milliliters of fluid lost.
  • More data is better: Aim for 10+ activities before training, and 15+ for even better accuracy.
  • Quality over quantity: It's better to have fewer activities with accurate fluid loss measurements than many with estimated values.

During Rides

  • Make sure your phone has a stable internet connection for predictions to be calculated and sent to your Garmin device.
  • Keep the app running in the foreground or ensure background activity is allowed (especially on Android).
  • Predictions update approximately every 2 minutes, so don't expect instant updates.
  • The fluid loss value shown is cumulative for your entire ride, not per interval.

Activity Management

  • If you make a mistake entering fluid loss, you can re-import the same activity to overwrite the previous entry.
  • Regularly review your saved activities to ensure data quality.
  • Delete activities with incorrect or estimated fluid loss values to improve model accuracy.
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