Distance-Adaptive Base Pace Estimation
What is This?
This feature helps you estimate a realistic pace for your upcoming race based on a recent race result. Tell RaceCraft about a race you've completed (like a 10K or half marathon), and it will predict an appropriate pace for your target race distance (like a 50K or 100K ultra).
How It Works
The app uses proven running performance models to predict your pace at different distances:
Step 1: Distance Scaling
Your recent race time is scaled to the new distance. As distances get longer, your pace naturally slows down due to increased fatigue.
Step 2: Ultra Adjustment
For races longer than a marathon (42.2 km), an additional slowdown is automatically applied. This reflects the more conservative pacing required in ultra-distance events:
- Double the distance → about 4-5% slower pace
- Four times the distance → about 9% slower pace
- Ten times the distance → about 15% slower pace
Step 3: Your Starting Pace
The result is your estimated base pace - what you'd run on flat, easy terrain. RaceCraft then adjusts this for climbs, descents, and technical terrain throughout your race.
How to Use It
1. Upload Your Race Route
First, upload the GPX file for your target race so RaceCraft knows the distance you're planning for.
2. Switch to "From Performance" Mode
In the Pacing section, toggle to "From Performance" instead of entering a pace manually.
3. Enter a Recent Race Result
Distance: Choose from common race distances: - 5K, 10K, 15K, Half Marathon, Marathon, 50K - Or enter any custom distance from 1 to 500 km
Time: Enter your finish time from that race - Use the format HH:MM:SS - Example: If you ran a 10K in 45 minutes, enter 0:45:00
4. Get Your Estimated Pace
Click "Calculate Estimated Pace" and you'll see: - Your estimated base pace for the new distance (min/km) - Your predicted finish time - A note if ultra-distance adjustments were applied
5. Apply the Pace to Your Plan
Click "Use This Pace" to automatically fill in your base pace and continue building your race plan. You can always adjust it manually if needed.
Examples
Example 1: 10K to 50K Ultra
Your Recent Race: - 10K in 45:00 (4:30 min/km pace)
Target Race: - 50K ultra
Estimated Base Pace: 5:32 min/km
Why slower? The distance is 5× longer, plus ultra-distance pacing is more conservative
Example 2: Half Marathon to 100K Ultra
Your Recent Race: - Half Marathon in 1:30:00 (4:16 min/km pace)
Target Race: - 100K ultra
Estimated Base Pace: 4:46 min/km
Why slower? You're nearly doubling the marathon distance, requiring a more sustainable pace
Example 3: 10K to Marathon
Your Recent Race: - 10K in 40:00 (4:00 min/km pace)
Target Race: - Marathon (42.2 km)
Estimated Base Pace: 4:21 min/km
Why slower? Standard distance scaling, no ultra adjustment needed
When Should You Use This?
Great for: - Stepping up to a longer race than you've done before - Planning your first ultra-distance event - Getting a starting point when you're unsure what pace is realistic - Using recent race results to guide your training plan
Keep in Mind: - Works best with recent races (within the last 3-6 months) - Assumes similar terrain - a road 10K won't perfectly predict a mountain ultra - Big distance jumps (10× or more) are less accurate - Your fitness and training since that race matter
Tips for Best Results
Use Your Most Recent Race: Results from the last few months are most accurate
Pick Similar Terrain: If you're planning a trail ultra, use a trail race result if possible
Adjust for Fitness Changes: If you've been training hard since your reference race, you might be faster than estimated
Be Conservative on Your First Ultra: Consider slowing the estimated pace by 5-10% to be safe
Try Multiple Reference Races: If you have several recent race times, try them all and see if the estimates are consistent
What Happens Next?
Once you apply the estimated pace, RaceCraft automatically adjusts it throughout your race for: - Climbs: Slower on uphills based on gradient and your climbing ability - Descents: Faster on downhills - Technical terrain: Slower on rocky, rooty, or difficult trails - Fatigue: Gradually slower as the race progresses
The pace you see in the estimate is just your starting point - the full race plan accounts for all the variables that will affect your actual pace on race day.