GPXray
Build your race strategy before race day.
Analyze terrain, simulate realistic pace, and understand where your race is decided.
Build your race strategy before race day.
- → Analyze the terrain
- → Simulate realistic pace
- → Find the decisive spots
🌤️ Race Day Weather Forecast
ITRA (International Trail Running Association) assigns performance scores based on your race results.
🔍 Find your ITRA scoreMost accurate option. Enter the distance, elevation gain, and finish time of a recent trail race. We'll predict your time on this course.
Adjust based on your climbing and descending ability compared to average. Strong climbers can run uphills; cautious descenders brake more on downhills.
How much you slow down in the final third of the race. Strong finishers fade less; long ultras fade more. Total finish time is preserved.
Select what you actually use during races. We'll suggest these in the Fuel column.
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Route
ITRA (International Trail Running Association) assigns performance scores based on your race results.
🔍 Find your ITRA scoreMost accurate option. Enter the distance, elevation gain, and finish time of a recent trail race. We'll predict your time on this course.
Adjust based on your climbing and descending ability. Slide right (cyan) = faster, left (orange) = slower.
How much you slow down in the final third of the race. Strong finishers fade less; long ultras fade more. Total finish time is preserved.
Select what you actually use during races. We'll suggest these in the Fuel column.
How do you handle terrain? This personalizes your pace predictions.
Average downhill stress per km (steepness × surface).
Course intensity:
• <50: Easy terrain
• 50-100: Moderate descents
• 100-150: Demanding descents
• >150: Quad-buster!
Pace loss depends on your runner level. - How it works
Based on total elevation gain, gain per km, and longest climb.
• <15 m/km — flat, leave them home
• 15-25 m/km — optional, personal preference
• 25-40 m/km — recommended for climbs
• >40 m/km — strongly recommended -
Approximately every ~45 min at flat terrain or AID stations.
Total carbs = est. finish time × g/h target.
Defaults: beginner 50, intermediate 65, advanced 80, elite 95.
Override under Advanced Options → My Fuel → Carbs (g/h).
Adapts to race time and terrain:
🍫 = Bar (early race, flat terrain)
🍬 = Gummy (mid-race or climbs)
⚡ = Gel (late race, quick energy)
🚰 = Water/refill at AID
⬇️ Dynamic Descent Load → Pace Loss
DDL builds up as you descend. When cumulative DDL approaches your DFT, quads fatigue → downhill pace drops.
💡 DFT = your downhill fatigue threshold (depends on runner level). Change level above to personalize.
Show formula
paceLoss = basePace × (1 + max(0, ratio–0.8)²) − basePace
This is a heuristic model, not medical advice.
Powered by Open-Meteo, a free weather API aggregating multiple models.
Models used:
• ECMWF (European)
• DWD ICON (German)
• GFS (American)
Forecasts may differ from other services due to different model blending.
open-meteo.com ↗
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📊 Course Details
Route Map
Course Load
Surface Analysis
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Race Strategy
Set your target pace for different terrain types. Pace is in minutes per kilometer (min/km).
Enter your target finish time and adjust the pace ratios for different terrain.
How do you handle terrain? This adjusts your pace predictions:
Calculated Paces
Use your ITRA Performance Index to estimate race time. You can enter your score directly or calculate it from a past race.
📊 Route Effort Points
🏃 Your ITRA Index
Enter a past trail race result to estimate your ITRA index:
⏱️ Estimated Race Time
Adjust pace multipliers relative to flat pace:
Your Race Strategy
Strategy Details
🚰 Leg Summary
| Leg | Distance | Elevation | Est. Time | Arrival |
|---|
| KM | Elevation Change | Terrain | Surface | AID Station | Stop | Fuel | Target Pace | Split Time | Race Time | Clock Time |
|---|