Weekly Running Mileage Planner
Plan your running base build using the 10% rule.
Enter current weekly mileage and goal to get a week-by-week schedule with built-in cutback weeks for injury prevention.
The 10% Rule
Never increase your weekly running mileage by more than 10% from one week to the next. This is the most widely followed injury-prevention guideline in distance running.
Weekly increase formula: Next week = Current week × 1.10
Cutback weeks: Every 3rd or 4th week, reduce mileage by 20% to allow recovery and consolidation of fitness. After the cutback, resume building from where you left off.
Weeks to goal (without cutbacks): Weeks = log(Goal / Current) / log(1.10)
Why it matters: Bones, tendons, and ligaments adapt more slowly than cardiovascular fitness. Increasing too fast overloads connective tissue before it has adapted — causing shin splints, stress fractures, and IT band syndrome.
Common mistakes:
- Jumping from 20 to 35 miles per week after a race
- Skipping cutback weeks when feeling good
- Restarting after injury at your previous peak mileage