12 Week Marathon Training Plan

Our 12 week marathon training plan is designed for runners looking to get ready to run 26.2 miles in just 3 months!

The 12 week marathon training schedule is best-suited to runners with at least 6 months of running under their belts; you should be able to run 10km continuously before you begin.

Think of this as more of a intermediate or even advanced plan than a beginners plan.

It ramps up the mileage and training quickly to suit your tight training schedule.

Scroll down to grab a copy of the free marathon training plan – available in both PDF and Google Sheets, so you can customise it! Otherwise, let me walk you through some of the finer points of training for a marathon in 12 weeks.

12 Week Marathon Training Plan

Can You Train For a Marathon in 12 Weeks?

Yes – 12 weeks is sufficient to get marathon-ready.

Thousands of runners have already used this plan and followed the guide in my book to do just that!

The main pre-requisite is that you should already have a foundation of running experience.

If you can run 10k without stopping right now, you’re in good shape to begin the 12 week marathon training plan.

The plan includes quite a rapid increase in weekly mileage, so it’s important to follow the plan closely, but also know when to take breaks – in other words, listen to your body.

The 12 week marathon training plan includes a 3 week taper period – meaning that your training actually peaks after 9 weeks, then the final 3 weeks are a gradual reduction in training volume to ensure you’re rested and prepped for your 26.2 mile race day.

12 Week Marathon Training Plan – Who Is It For?:

Runners who have established an initial running base, or have an existing good fitness level.   You should be able to run 10km without stopping.

You don’t need to be an advanced, or very experienced runner, to follow this free plan – but you do need to have built up some running experience.

The 12 week marathon training plan’s weekly mileage builds fairly quickly, so it’s important that your body is already well-adapted to running before starting.

How Long?: 

3months // 12 weeks.

This includes 9 weeks of gradually increasing mileage, peaking with a 21 mile long run 3 weeks before your marathon.

The final 3 weeks are your taper period – we gradually reduce training volume over those 3 weeks to ensure that when you get to your start line you are rested, recovered, and well-fuelled.


This 12 week marathon training plan has you working out five days a week – four days of running and a day of cross-training, with two days off.  

I always include one day of cross training in my marathon training plans – for me, cross-training is the secret sauce that makes you less injury-prone, stronger, faster, and boosts your endurance. However some runners choose to skip the cross training and take an additional rest day.

If that’s you, no worries!

12 week marathon training plan

12 Week Marathon Training Plan Workouts Explained

Given the relatively short training time, the important thing to focus on is building your endurance rather than speed.   

Attempting to improve both endurance and speed in this short window is likely to stress your system too much, and will quickly lead to injury, illness, fatigue, burn-out, and exhaustion.

That’s why a balanced marathon training plan is so important; you need a plan which adds the requisite mileage while pushing the limits of your endurance, but allowing time for recovery too.

Regular Training Runs

There are 3 regular training runs per week in the 12 week marathon training plan. 

Your regular training runs should be performed at a sustainable pace – unless you have a specific pace target, aim to run at a conversational pace throughout. In other words, maintain a pace at which you could comfortably hold a conversation.

These runs are all about adding to your weekly mileage and honing your running economy and form.

Long Slow Runs

For your Long Runs, the aim is simply to get your body used to running for a long time – so take them easy, don’t push yourself.  

These long runs are all about increasing your endurance, specifically;

  • Improves your muscles’ ability to perform after running for hours (time to fatigue)
  • Improves your cardiovascular system’s efficiency while running
  • Boosts your mitochondria (i.e. your body’s fuel-burning ability), so your body is better equipped to turn energy stores into muscle power on marathon day
  • Mental and logistical preparation for running long distances!

If necessary, take occasional walking breaks – just try to maintain a good rhythm and not stop completely

Cross Training

Cross-training is a great way to keep fit and ensure your marathon training does not negatively impact other parts of your body.  Many runners have other sports and hobbies they don’t like to neglect when in training, so you can do these on Thursdays if you want.  Cycling, swimming and yoga are examples of recommended cross-training activities.

Just avoid high impact of very intense workouts – I recommend giving activities like spin classes and CrossFit a rest when following the 12 week marathon training plan, otherwise you increase the risk of injury and burnout.

Run Intensity and Rest Days

When it comes to run training intensity, don’t overdo things – given you only have 12 weeks to prepare, speed is secondary to getting the miles in.  

If your body is worn out, allow it some rest.  

Don’t be too worried about skipping a training day during the 12 week marathon training plan – but if at all possible, don’t miss your weekly long runs.

Get The Complete Guide

My guidebook, Marathon in 3 Months, is available now for instant download.  It maps out the complete training strategy and rationale behind the 12 week marathon training schedule supplied.   It walks you through your week-by-week training and preparation to get you to the finish line in under four hours. 

The guidebook goes into detail with the training plan, and includes many practical tips for marathon preparation.

Download The Training Plan Here

Enter your email and I’ll send you this free training plan now, in PDF and Google Sheets formats (completely customisable), in both miles and kilometers.  

12 Week Marathon Training Plan 1

Wait…Why Do You Need My Email?

Hey, it’s Thomas!
I’m going to send you links to download PDF and Google Sheets versions of this training plan, all completely free!

The Google Sheets version is completely customizable, meaning you can mix up the training plan to suit your own schedule.

Most websites charge (ridiculous) fees for access to this kind of resource, but I like to share as much of our resources as I can for free with anyone who takes the time to check out Marathon Handbook!

When you enter your email address above, I’m going to send you the training plan and a few other totally free marathon training guides and resources. There’s nothing salesy or scammy here – just sharing of the best marathon training knowledge and resources!

I hope you take the leap and let me help you with your marathon training journey !

Check Out The Premium Version of The 12 Week Marathon Training Plan . . .

We’ve teamed with TrainingPeaks to offer a premium version of the 12 Week Marathon Training Plan:

Access the plan via the TrainingPeaks website and app, track your workouts in real-time against the plan, and get performance data analysis on your progress.

Check out the premium 12 week marathon training plan here!

12 Week Marathon Training Plan 2
trainingpeaks training plan

The most comprehensive plan you will find

Rated 5 out of 5
October 28, 2019 7:05 pm

I had run a couple of half marathons and was in reasonable shape coming into the plan and it was a good rise in intensity throughout. You need to want to do an event like this – I was getting up at 3am to get my long run in before kids weekend sport etc and this was hard. When you combine the plan with the online community through the Marathon Handbook FB page and website, you get complete support. Have used this plan with great success and now looking at upping the pace in the marathon space… GREAT JOB!

Rob McCaw

Broken links - can't get the plan

Rated 5 out of 5
August 2, 2022 6:43 am

Hi guys,
Thanks for all the useful information here, it really helps me in my running journey. I used your 6-month plan to prep for a marathon, and it was a great experience! Now I wanted to download the 12 weeks plan for a half marathon but it seems to be a problem, and I can’t find the place to leave my email address / download the plan. Since I didn’t find any other contact info, I’m leaving this comment here in the hope you will read it and can send me the plan. I would really appreciate cause I know how much easier it makes the preparation. Thank you!


Couch to Half Marathon

Rated 5 out of 5
July 24, 2022 1:25 am

So I am a fairly sedate person, but this year I turned 40, and for some odd reason I wanted to start doing some running. I’ve done some 5k races 5-6 years ago, but was never very ino running. There’s a run coming up in my home town at the end ofJuly, but it’s only a half marathon or 5k and I wanted to challenge myself to something harder than the 5k, so I started the couch to Half Marathon plan, but was fairly confident I wouldn’t be able to handle the mileage. It’s week 14 and although I haven’t been perfect, I’ve actually been able to get most of the workouts in. I have been totally amazed. 1 week until the half, and although I won’t be breaking any speed records, I’m fairly confident I’ll finish, which is my real goal. Thanks to Thomas for having a plan that works, even for old non active people 😁, I’m super excited and very grateful!!


I would like to download this training plan

Rated 5 out of 5
June 30, 2022 11:42 am

But I don’t know how?!

Janko Radovanovic

Sending Training Plant

Rated 5 out of 5
May 28, 2022 12:24 am

Please send me the training plan for Marathon in 6 months

Gita Dimarsandy


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Proven Training Plans by a UESCA-certified Running Coach 

Every one of our training plans has been developed by Thomas Watson, a UESCA-certified running coach.

Thomas is also a podium-finishing ultra-marathon runner, and has dozens of marathons under his belt.

Each training plan has been road-tested by hundred of runners, refined and improved – and are free to download and customise to suit your needs!