Pfitzinger 18/55
Pfitz 18/55 is the Pfitzinger marathon plan from Advanced Marathoning: 18 weeks of training, peaking at 55 miles (89 km) per week. It combines long runs, tempo work and midweek medium-long runs.
Before choosing 18/55, check whether its starting mileage and five-day schedule fit the running week you can sustain. Our guide to choosing a training plan walks through those trade-offs.
- Duration
- 18 weeks
- Frequency
- 5 days / week
- Time / week
- 6–9 hrs
- Intensity
- High
- Start if you can…
- You're already running 30+ mpw with a 10+ mile long run
- Builds up to
- 20–22 mi long runs; 55 mpw peak weeks
Best for
- ✓Experienced marathoners chasing a big PR or BQ
- ✓Runners who thrive on structure and mileage
- ✓Those with time for five running days and midweek longer runs
Why the community recommends this
The most-discussed serious marathon plan on r/AdvancedRunning. The signature midweek medium-long runs build enormous endurance — runners swear by the results, and by how demanding it is.
Check paces against your current fitness
Enter a recent race result to estimate training paces. A goal time shows the fitness that goal requires.
How the plan is structured
- Five running days per week, peaking at 55 miles (89 km)
- Lactate-threshold (tempo) runs of 4–7 mi at ~15K–half effort
- Midweek medium-long runs of 11–15 mi — the trademark element
- VO2max intervals in the sharpening phase
- Long runs up to 20–22 mi at controlled effort
- A structured 3-week taper
Strengths
- +Proven for big PRs and Boston qualifiers
- +Detailed, periodized, leaves nothing to chance
Trade-offs
- −High volume + intensity — demands real fitness and time
- −Unforgiving if you start under-prepared
We summarize this popular plan and link to the original rather than reproduce its copyrighted week-by-week schedule.
If the starting mileage or five-day week does not fit your current training, compare other marathon plans before choosing a schedule.
anystride plans are educational summaries of community-trusted training methodologies, not medical or individualized coaching advice. Listen to your body, and consult a doctor before starting a new program.
Want help adapting your training?
A free plan gives you a schedule. If your availability or goals change, a coach can help you decide what to adjust. Ask what individual review and communication their service includes.