FIT vs GPX: When to Use Each Format for Your Fitness Data

What's the difference between FIT and GPX files? FIT is Garmin's binary format optimized for fitness devices with full sensor support, while GPX is a universal XML format focused on GPS data exchange. FIT is best for recording and device use; GPX is best for sharing and cross-platform compatibility.

This guide helps you understand when to use each format.

Quick Comparison

FIT Format: Strengths and Use Cases

What FIT Does Best

Native Sensor Support FIT natively stores:

• Heart rate
• Power (watts)
• Cadence
• Speed
• Temperature
• Running dynamics
• Cycling dynamics

Structured Workout Data

• Lap and interval markers
• Workout steps and targets
• Training effect metrics
• Recovery data

Efficient Storage

• Binary encoding = smaller files
• Faster sync to devices
• Less storage space needed

When to Use FIT

FIT Limitations

• Not human-readable: Can't view in text editor
• Limited platform support: Some apps don't accept FIT
• Garmin-centric: Best within Garmin ecosystem
• Harder to edit: Requires specialized tools

GPX Format: Strengths and Use Cases

What GPX Does Best

Universal Compatibility GPX works with:

• All GPS devices
• Every mapping application
• All fitness platforms
• Any text editor

Human-Readable Format

<trkpt lat="51.5074" lon="-0.1278">
  <ele>11</ele>
  <time>2024-12-08T10:00:00Z</time>
</trkpt>

Easy Editing

• Modify in any text editor
• Remove privacy-sensitive points
• Split or merge tracks
• Change metadata

When to Use GPX

GPX Limitations

• Larger file sizes: XML overhead
• Limited sensor data: Extensions not universally read
• No lap structure: Can't preserve intervals
• No workout structure: Just track points

Sensor Data Comparison

Heart Rate

Reality: Most apps importing GPX don't read heart rate extensions.

Power Data

Reality: For cycling power analysis, FIT is essential.

Cadence

Structured Workouts

Conclusion: If you need sensor data or workout structure, use FIT.

Platform Compatibility

Platforms That Accept Both

Platforms with Format Preference

Use Case Scenarios

Scenario 1: Recording a Workout

Best choice: FIT

Why:

• Full sensor data captured
• Laps and intervals preserved
• Smaller file size on device
• Native Garmin integration

Scenario 2: Sharing a Route with Friends

Best choice: GPX

Why:

• Works with any device/app they have
• No compatibility concerns
• Easy to send via email
• They can edit if needed

Scenario 3: Analyzing Training Data

Best choice: FIT

Why:

• Complete power/HR data
• Lap-by-lap analysis possible
• Works with analysis software
• Training metrics preserved

Scenario 4: Planning a Route

Best choice: GPX (then convert)

Why:

• All route planners export GPX
• Easy to preview in multiple apps
• Convert to FIT for device use

Scenario 5: Backup & Archival

Best choice: Both

Why:

• FIT preserves all data
• GPX ensures future readability
• Double backup = peace of mind

Scenario 6: Uploading to Multiple Platforms

Best choice: Start with FIT

Why:

• FIT has all the data
• Convert to GPX only when needed
• Avoid data loss from GPX first

Data Loss in Conversion

FIT → GPX Conversion

Preserved:

• GPS coordinates ✅
• Timestamps ✅
• Elevation ✅
• Basic track structure ✅

Lost or reduced:

• Lap markers ❌
• Full sensor data reliability ⚠️
• Workout structure ❌
• Device-specific data ❌

GPX → FIT Conversion

Preserved:

• GPS coordinates ✅
• Elevation ✅
• Basic metadata ✅

Generated:

• Timestamps (from speed input) ✅

Not available:

• Sensor data (never in GPX) ❌
• Lap structure ❌

Decision Flowchart

Need to share route with others?
├── Yes → Use GPX
└── No ↓

Recording activity with sensors?
├── Yes → Use FIT
└── No ↓

Using Garmin device?
├── Yes → Use FIT
└── No ↓

Need to edit the file?
├── Yes → Use GPX
└── No ↓

Long-term backup?
├── Yes → Keep both
└── Either works

Converting Between Formats

FIT to GPX

Use our FIT to GPX Converter when:

• Sharing routes with others
• Uploading to GPX-only platforms
• Creating editable route files

See: How to Convert FIT to GPX

GPX to FIT

Use our GPX to FIT Converter when:

• Uploading planned routes to Garmin
• Creating course files for navigation
• Transferring routes from planning apps

See: How to Convert GPX to FIT

Best Practices

For Athletes

1. Record in FIT (or your device's native format)
2. Keep original FIT files as primary backup
3. Convert to GPX only when sharing
4. Use GPX for route planning, convert to FIT for device

For Route Sharing

1. Export as GPX for maximum compatibility
2. Test the GPX imports correctly before sharing
3. Remove start/end points if privacy is a concern

For Analysis

1. Use FIT files for training analysis
2. Import to analysis software (TrainingPeaks, WKO5, etc.)
3. Keep structured data intact by avoiding unnecessary conversion

Other Formats to Consider

TCX (Training Center XML)

• Middle ground between FIT and GPX
• XML-based (readable) with lap support
• Good for platform transfers

See: FIT vs CSV vs TCX: Choosing the Right Format

CSV (Comma-Separated Values)

• Best for spreadsheet analysis
• Loses all structure
• Universal data format

See: How to Convert FIT to CSV

KML (Keyhole Markup Language)

• Google Earth native format
• Great for visualization
• GPS-focused like GPX

Related Resources

Converters

• FIT to GPX Converter
• GPX to FIT Converter
• FIT to TCX Converter
• FIT to CSV Converter

Guides

• Complete Guide to GPX Files
• Complete Guide to Garmin FIT Files
• How to Convert FIT to GPX
• How to Convert GPX to FIT
• Best Apps for Viewing GPX Files

Summary

Rule of thumb: Record in FIT, share in GPX.

Both formats have their place. Understanding their strengths helps you make the right choice for each situation.