Marathon Training Plan — 16 Weeks to a Sub-4 Marathon

Marathon Training Plan — 16 Weeks to a Sub-4 Marathon

A phase-by-phase, 16-week program built to get you across the line in under 4 hours

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Running a marathon in under 4 hours takes more than motivation — it takes a plan. This structured 16-week training plan breaks your buildup into clear phases: base building, marathon-pace work, peak mileage, and taper, so you show up on race day ready to hold 9:09 per mile (5:41/km) from start to finish. RunRun.fr turns this framework into a free, personalized plan that adapts week to week to your fitness and schedule.

Why choose RunRun?

16-week phase-based structure

Four phases — base, build, peak, and taper — spread across 16 weeks with 3 to 4 sessions per week. Every workout comes with pace, duration, and purpose spelled out.

Smart progress tracking

RunRun reads your feedback after every session and adjusts the weeks ahead to match your fitness level. No cookie-cutter plans.

Built around your race

Enter your race date, current fitness level, and weekly availability. RunRun builds a 16-week plan around YOUR calendar, not a generic template.

Recovery built in

Dedicated taper weeks and easy recovery days are baked into the schedule so you toe the line fresh, not fried.

Workout variety that builds real fitness

Intervals, tempo runs, easy runs, long runs... each workout type targets a different piece of marathon fitness.

Free to start, no strings attached

No credit card needed. Creating an account and generating your plan is free. Sign up and start your marathon prep right away.

16-week sub-4 marathon plan, phase by phase

W1

Week 1 — Base Phase Begins

Easy mileage only while your body adapts to the training load. Weekly volume: 20 to 25 miles.

  • •45-minute easy run
  • •50-minute easy run + 6 strides
  • •75-minute long run at easy pace
W4

Week 4 — First Tempo Work

The base phase wraps up with your first tempo session, priming your body for marathon pace. Weekly volume: 25 to 30 miles.

  • •45-minute easy run
  • •2 x 15 minutes at tempo pace (8:51/mile) — 3-minute recovery jog
  • •90-minute long run with 20 minutes at marathon pace (9:09/mile)
W8

Week 8 — Midpoint Build

Halfway through the plan, marathon-pace segments get longer and weekly mileage keeps climbing. Weekly volume: 35 to 40 miles.

  • •50-minute easy run
  • •3 x 10 minutes at tempo pace — 2:30 recovery jog
  • •40-minute easy run + 8 strides
  • •2-hour long run with 40 minutes at marathon pace
W11

Week 11 — Peak Mileage

The highest-volume week of the entire plan, capped by the longest run of the cycle. Weekly volume: 40 to 45 miles.

  • •50-minute easy run
  • •3 x 10 minutes at tempo pace — 2:30 recovery jog
  • •20-mile long run with the final 4 miles at marathon pace (9:09/mile)
W12

Week 12 — Taper Begins

Volume drops about 30% while intensity stays sharp. The taper phase (weeks 13 to 16) starts here, letting your body absorb months of training before race day. Weekly volume: 28 to 32 miles.

  • •40-minute easy run
  • •2 x 10 minutes at tempo pace — 3-minute recovery jog
  • •30-minute easy jog

Tips for running a sub-4-hour marathon

1

Lock in your goal pace

The classic rookie mistake is starting too fast. Your marathon pace is about 9:09 per mile. Set it on your GPS watch and hold it, especially through the first 10 miles.

2

Build a deep aerobic base

70 to 80% of your training volume should be run at easy, conversational pace. That aerobic base is what lets you hold pace when the race gets hard.

3

Dial in your fueling

Start carb-loading three days out. On race day, aim for 60 grams of carbs per hour from gels or sports drink, and grab fluids at every aid station. Never try anything new on race day — test it all in training.

4

Don't skip strength training

Two short strength and core sessions a week lower your injury risk and sharpen your running economy.

5

Train your mind, too

Break the race into chunks — 5K, the half, mile 20, the finish. Prepare a few mantras and visualize crossing the line. The wall at mile 20 is as much mental as physical.

landing.faq

How many days a week should I run for a sub-4 marathon?
We recommend 3 to 4 runs a week across this 16-week plan — enough to build fitness without burning out. RunRun adjusts the weekly session count to match your schedule.
Is this training plan actually free?
Yes, creating an account and generating your 16-week plan is free. RunRun offers an optional Premium subscription for extras like syncing and detailed stats, but the plan itself stays free. Sign up and your plan is ready immediately.
What fitness level do I need before starting?
You should be able to run a 10K in under 55 minutes or a half marathon in under 1:52. If you've been running consistently for at least 6 months, this 16-week plan is a realistic target.
Does the plan adjust to how I'm actually running?
Yes. RunRun factors in your past race times, weekly availability, and post-run feedback to update the plan in real time.
Can I sync my GPS watch (Garmin, Strava)?
Yes, RunRun connects with Strava so your runs match up with your sessions automatically. RunRun workouts can also be pushed to your Garmin watch through Garmin Connect.

Ready to tackle a sub-4 marathon?

Create your free RunRun account and get a 16-week training plan built around your fitness level and race date.

Build my free plan