Pfitzinger 18/55
The famous 'Pfitz' plan from Advanced Marathoning: 18 weeks peaking at 55 mpw, built on lactate-threshold runs and midweek medium-long runs.
- Duration
- 18 weeks
- Frequency
- 6 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 6 days/week
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.
Run this plan at the right paces
Get your easy, tempo, and interval paces from a recent time or goal.
How the plan is structured
- 5–6 running days, peaking around 55 mpw
- 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.
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.