How long does marathon training take? A practical, expert answer
Last update Dec 4th, 2025, by Etienne Durocher
Short answer: it depends. For most people the realistic timelines fall into three buckets: new runners — ~16+ weeks, half-marathon fit — ~12 weeks, and already-in-shape experienced runners — ~9–10 weeks. Those are good rules of thumb, but the right plan depends on your recent mileage, injury history, goals, and life schedule.
Why there is no single answer
Marathon training is not a single recipe. Training time is driven by two things: your starting fitness and your goal. A first-time runner needs more weeks to build durable aerobic base and connective tissue resilience. A runner who is already doing 30–50 minutes of steady running several times per week can compress the build safely. Experts and classic training frameworks reflect that range rather than one fixed number. (Hal Higdon)
Practical timelines (with rationale)
Beginner / brand-new runner: 16 weeks or more
If you’ve never regularly run beyond a few kilometres, assume 16 weeks minimum, and consider 18–24 weeks if your weekly mileage is very low. This gives time to progress long runs slowly, add easy weekly mileage, and include recovery weeks so the week-to-week load doesn’t spike. Hal Higdon’s novice programs and many coaching frameworks favor 18 weeks for true beginners because they start with very short long runs and build conservatively.
Runner with half-marathon experience: about 12 weeks
If you can comfortably run a half marathon within the last 3–6 months and are logging regular weekly mileage, 12 weeks is a reasonable plan to shift from half-marathon fitness to full marathon readiness. That assumes you’re already doing steady long runs of 10–15 km (6–10 miles) and can increase your long run mileage progressively. Many intermediate plans and practical guides recommend 12–16 weeks for this group. (Jason Fitzgerald)
Fit, experienced runner: 9–10 weeks
If you run regularly, maintain decent weekly mileage (30–60 km / 20–40 mi), and have previous marathon experience, you can often prepare in 9–10 weeks for a specific goal race—especially if you’re using a focused block (marathon pacing, a couple of quality sessions per week, and a sensible long run progression). Coaches like Jack Daniels give templates for shorter final buildup blocks (including 12- and 18-week variants) you can adapt when the base is already present.
What the evidence and case studies say
Elite case studies often use individualized 12–16 week blocks for the final preparation phase. For example, nutrition and periodization case studies of elite marathoners frequently report individualized 16-week race preparations. That shows 16 weeks is a tried and tested block at the highest level when carefully managed. PubMed+1
A recent quantitative review analyzing 92 sub-elite 12-week pre-marathon plans highlights that many training frameworks compress the final preparation into a 12-week focused phase—especially for runners who already have base fitness. This supports the idea that 12 weeks can be effective when the athlete arrives with preparation. ResearchGate
(Links: Hal Higdon novice programs, Jack Daniels training notes, PubMed case study, review of 12-week plans — see citations above.)
What “ready to start” looks like
Before you begin a marathon plan aimed at the timelines above, check these markers:
You can run 3–4 times weekly consistently for at least 6–8 weeks.
You already have recent runs close to 10–12 km for the 12-week candidate, or 16–20 km for an experienced runner.
You have no persistent injury or unmanaged niggles. If you do, add weeks and prioritize rehab.
This prevents big mileage jumps and lowers injury risk.
Common mistakes people make when rushing
Jumping mileage too fast. That’s the leading cause of injury. Progressive increases matter more than a flashy early long run.
Ignoring strength work. Skipping strength and stability work increases risk and limits progression—allow an extra few weeks if you must add a new cross-training habit.
Treating the long run as the only key session. Quality workouts (tempo, marathon pace, interval work) and easy aerobic miles are equally important to build specific fitness.
How I use these timelines as a coach (my approach)
I use your suggested buckets as my baseline: beginner = 16+ weeks, half-marathon fit = ~12 weeks, experienced = 9–10 weeks. From there I adapt using simple diagnostics: current weekly mileage, recent long run, injury history, and life stress. If someone is time-poor (three runs/week), I lengthen the plan and add targeted cross-training and strength sessions to preserve load and prevent injury. If someone has a solid base and a target time, I compress the plan into a focused block but keep conservative long runs and scheduled recovery. (This matches the logic used by classic frameworks and case studies.)
A sample decision guide (quick)
New to running or inconsistent: start now — 16–24 weeks.
Comfortable with a half marathon in the last 6 months: 12–16 weeks.
Running regularly, past marathons, goal race is 9–10 weeks away: you can prepare with a focused block if you’re consistent and injury free.
Bottom line and call to action
How long does marathon training take? It depends on where you start. Use these practical guidelines: 16+ weeks for new runners, ~12 weeks for half-marathon fit runners, and ~9–10 weeks for experienced, already-in-shape runners. If you want a personalized timeline that factors in your recent mileage, injury history and life schedule, I can assess your current training and give a precise, safe plan that fits your timeline and goal.
If you’d like, I’ll create a custom 12- or 16-week plan for you (or a 9-week tune-up), tailored to your current mileage and availability. Book a free consult or drop your current weekly mileage and recent long run and I’ll map out Week 1–Week X right away.
