My First Marathon: 20-Week Plan to Finish

My First Marathon: 20-Week Plan to Finish

The free training plan for runners who want to complete their first marathon — no time goal obsession

Create my marathon plan

The marathon is not just for elites. Any regular runner who can train three times a week can cross the 26.2-mile finish line. This 20-week plan is built for runners who already jog 45 to 60 minutes and want to finish their first marathon on their feet — without chasing a time goal. RunRun guides you session by session, from your first long run to race morning.

Why choose RunRun?

20 weeks of structured progress

The plan builds through 4 phases: base (W1-5), development (W6-10), peak (W11-16), taper (W17-20). Every week is planned out.

Easy aerobic running (zone 2)

70% of sessions are run at conversational pace — you should be able to speak in full sentences. This is the foundation of every successful marathon.

Weekly long run

The cornerstone of the plan: one long run per week, progressing from 1h30 to 3h15 in week 15. Training runs never exceed 32 km.

Injury prevention built in

Recovery weeks every 4 weeks, strict 10% load increase rule, and strength exercises included throughout.

Finisher — that's the goal

This plan is calibrated for experience, not pace: cross the finish line upright and smiling after 42.195 km.

Key phases of the beginner marathon plan

W1

Week 1 — Foundation

Get your body used to running 3 times a week at conversational pace.

  • •Session 1: 40 min easy (zone 2)
  • •Session 2: 35 min easy + 10 min light fartlek
  • •Session 3: 50 min long easy run
W5

Week 5 — End of base phase

Weekly volume reaches 1h45 of actual running.

  • •Session 1: 45 min easy
  • •Session 2: 40 min with 3×5 min at half-marathon effort
  • •Session 3: 1h15 long run
W10

Week 10 — Load building

The long run exceeds 2 hours. Your body learns to handle prolonged effort.

  • •Session 1: 50 min easy
  • •Session 2: 45 min with 2×10 min at marathon effort
  • •Session 3: 2h05 long run
W16

Week 16 — Peak week

The highest point of training: 3h05 long run, the longest effort in the whole plan.

  • •Session 1: 55 min easy
  • •Session 2: 50 min with 3×8 min at marathon effort
  • •Session 3: 3h05 long run (28-30 km)
W20

Week 20 — Race week

Full taper. Save your energy for the big day.

  • •Monday: complete rest
  • •Wednesday: 25 min very easy jog
  • •Saturday: 15 min shakeout run
  • •Sunday: MARATHON — enjoy every step!

Tips for completing your first marathon

1

Train as slow as you can

Zone 2 (conversational) pace for most runs, even if it feels too easy. Race day speed will come from consistency, not training hard.

2

Test your race nutrition on long runs

Gels, energy bars, sports drinks — train your gut before race day, not on it. Never try anything new on race morning.

3

Honour your recovery weeks

Every 4 weeks, volume drops 20-30%. These are the weeks your body actually adapts and gets stronger. Never skip them.

4

Use the RunRun pre-race checklist

Race bib, gels, broken-in shoes, tested kit — the checklist means nothing is forgotten on race morning.

5

Start the first 10 km slower than you think you should

The number-one mistake in a first marathon: going out too fast. Think of the first 32 km as a very long warm-up.

landing.faq

How long does it take to train for a first marathon?
20 weeks is the recommended minimum when starting from a base of 45-60 minutes of regular running. This timeframe allows for gradual load progression and reduces injury risk significantly compared to shorter prep cycles.
Do I need to have run a half marathon before a full marathon?
It's strongly recommended but not mandatory. What matters most is that you've been running consistently for at least 6 months and are comfortable running for 60 minutes. A recent half-marathon result also gives you a useful data point for setting your marathon pace.
What pace should I target for my first marathon?
Conversational pace — the speed at which you can comfortably hold a conversation. If you have a half-marathon time, add roughly 1h40 to 2h for your marathon. For a pure finisher goal, target 6 to 7 minutes per kilometre depending on your fitness level.
Is it okay to walk during a beginner marathon?
Absolutely. Walking through aid stations is actually a smart strategy for taking on gels and water. Many first-time finishers incorporate walking breaks in the final kilometres. The goal is to finish, not to run every single step.
How many kilometres per week do I need to run to train for a marathon?
For a beginner finisher plan, peak weekly volume sits between 40 and 55 km, reached during weeks 14-16. You build to this gradually, starting around 25-30 km per week in the early phases.

Ready for your first marathon?

Start your free beginner marathon plan on RunRun. 20 weeks of preparation, session-by-session tracking, pre-race checklist included.

Create my marathon plan