Every week, mapped out.
Runs and strength sessions scheduled together — each placed where they won't wreck your key workouts.
How your plan is built
Five inputs. Grounded in what actually predicts marathon performance.
1
Weeks to race
Defines your phase structure
Determines how long each phase runs and how much time is available to build before the taper.
2
Current weekly mileage
Sets your volume ceiling
Determines your starting point and how aggressively the plan can build.
3
Goal time
Sets your training load
Sets your training intensity and marathon-pace volume. Faster goals mean more threshold work and higher mileage.
4
Running days
Determines session mix
Sets how many sessions per week and which types fit in.
5
Include strength training
Kept in the picture
Tell me whether you lift. Strength sessions are scheduled around your runs, not on quality days or adjacent to the long run.
The Science
Built on Pfitzinger, improved
Pfitz is the gold standard for volume progression and phase structure. I keep what works and fix what doesn't.
What I keep: the 10% progression rule, long run targets, recovery week cadence, and the Base → Build → Peak → Taper arc. What I change: intensity distribution is polarized (80% easy / 20% hard) to eliminate the gray-zone fatigue that Pfitz's medium-long runs create. Phase order is reversed — threshold work comes before VO2max in early phases, then marathon-pace dominates the final 6–8 weeks. And marathon-pace volume is dramatically higher than Pfitz prescribes (~14 miles over 12 weeks). Modern coaching prescribes 5–10× that.
Source: Pfitzinger & Douglas, Advanced Marathoning (3rd ed.)
Training phases
Five phases, each with a distinct purpose. The taper is always 3 weeks — everything else scales to your timeline.
General Fitness
Optional phase for 20+ week plans. Easy aerobic volume only — no quality sessions. Builds tissue tolerance before heavier training begins.
Base
Aerobic foundation. Tempo runs introduce lactate threshold work. Easy volume builds the engine.
Build
Early: tempo + VO2max intervals raise your ceiling. Late Build shifts toward marathon pace.
Peak
Marathon-pace dominant. The final 6–8 weeks are the most race-specific of the entire plan.
Taper
3 weeks. One light tempo session in Week 1. Full easy running from Week 2 through race day.
Strength training is performance, not maintenance
A 2024 meta-analysis of 31 studies and 652 runners puts heavy resistance training on the same performance tier as lactate threshold work.
Heavy resistance (≥80% 1RM) combined with plyometrics improves neuromuscular efficiency, tendon stiffness, and running economy. The effect size is meaningful (ES = −0.426). I schedule strength on easy run days, after the run, never adjacent to quality sessions or the long run. Volume tapers with the plan: 2×/week resistance in Base and Build, 1×/week in Peak, and zero from Taper Week 2 through race day.
Source: Grgic et al., Sports Medicine 2024 — meta-analysis, 31 studies, 652 runners (PMC11052887)
Zack
Edmonton, AB
Why I built this
I ran my first marathon in September 2025 in 3:52. I'm trying to run 3:20 at Victoria BC this year and I eventually want to qualify for Boston.
I wanted a program that fit how I actually train. I was using ChatGPT for plans, Google Sheets for tracking, and I didn't want to pay for Runna.
I believe training plans should be free. Eventually, I do want to build out higher quality features like adaptive training.
⚡
Early access
I'm looking for people to try this and tell me what's wrong with it. Please roast it.
zack@athlos.runBuild your plan.
Your plan generates in seconds, built around your race and numbers.