Contents
Long Run Progression Calculator
Plan your long run buildup for marathon or half marathon training. Get a week-by-week progression with built-in cutback weeks.
How to Build Your Long Run Safely
The long run is the cornerstone of distance running training, but building it too quickly is a common cause of injury. This calculator creates a sustainable progression plan.
Key Principles
- Increase by 1-2 miles per week - Most runners can safely add 1-2 miles to their long run each week
- Cutback every 3-4 weeks - Reduce long run distance by 20-30% to allow adaptation
- Peak 2-3 weeks before race - Your longest run should be 2-3 weeks out, not race week
- Cap at appropriate distance - For marathons, 20-22 miles is typically sufficient
Long Run Guidelines by Race
| Race | Minimum Peak Long Run | Ideal Peak Long Run |
|---|---|---|
| Half Marathon | 10 miles | 12-14 miles |
| Marathon | 16 miles | 20-22 miles |
Time vs. Distance
Many coaches prefer time-based long runs over distance:
- Half marathon training: Build to 90-120 minutes
- Marathon training: Build to 2.5-3.5 hours
This approach naturally adjusts for pace differences between runners.
Common Mistakes to Avoid
Running Long Runs Too Fast
Your long run pace should be 60-90 seconds per mile slower than marathon pace. If you can't hold a conversation, you're going too fast.
Skipping Cutback Weeks
Cutback weeks aren't lazy—they're when adaptation happens. Your body builds fitness during recovery, not during the workout itself.
Starting Too Ambitious
If your current long run is 6 miles, jumping straight into a 16-week marathon plan with 10-mile first long runs is a recipe for injury. Build your base first.
When to Adjust the Plan
Consider adding extra time or reducing the buildup if:
- You're coming back from injury
- You're new to the distance
- You're running in challenging conditions (heat, altitude)
- You're over 50 or injury-prone