Training: Marathon

Do you want to run a marathon? Whether you’re a beginner or an experienced runner, we look at how you can train, with advice on creating your own marathon training plan.

What is a marathon?

A marathon – a running event over 26 miles and 385 yards (or 42,195m) – is one of the classic running events. Indeed, in the minds of many people, it is the classic running event.

Just crossing the finish line is often enough for many runners. They’ve ticked the box, achieved a goal, got the t-shirt (and medal), and can move onto new challenges.

For those who are motivated by breaking personal bests, or running fast times, a marathon offers an extra element of difficulty compared to shorter events. Running a 5K, for example, at your absolute limit is undoubtedly hard, but should you fall short of your goal, you stand a good chance of being ready for another attempt within a week or two.

If you don’t manage to achieve your goal in a marathon, however, it might be months before your body has recovered enough to try again. This pressure to get it right on the day adds to the drama of marathon running.

Don’t let the distance intimidate you

Humans are well suited to covering long distances. Provided there isn’t a physical or medical barrier to participation, most people could probably cover the marathon distance if they absolutely had to. But, it might be hard, uncomfortable, and not a lot of fun.

What training does is increase the likelihood of finishing injury-free, within your target time, and with a smile on your face. The better you prepare before the event, the better your chances of achieving your goals.

Long runs

A marathon is unmistakably an endurance event. Even a professional needs to be prepared to run for in excess of two hours. Most marathoners will be out on the course far, far longer than that.

To prepare yourself for running for such a long time, you need to do lots of long runs. How long these runs should be, and how many you should do, is open to debate. It depends on your running history, injury susceptibility, and how much time you are able or willing to give to running.

Runners will start with a distance they know they can manage, and gradually increase the distance over the training plan. The correct maximum long run distance for you will be one that balances:

  • Getting enough miles in to get strong enough – vs – the need to recover properly.
  • The confidence boost of knowing you can run a long way – vs – avoiding mental exhaustion.
  • Your desire to run – vs – making time for all the other important things in your life.

From a purely physical training point of view, the first point is important to get right. Running is about stress and rest. The more stress we add, the more rest we need. If you run so far on a weekend long run that you’re absolutely wiped out for the rest of the week, it isn’t going to benefit your running.

This is why the optimum long run distance is individual to each runner, and hard to define. It can take experience to work out what works best for you, but to start off with it probably isn’t necessary to exceed 3 hours, or 20 miles of running – whichever is the lesser of the two. Any more than that, and you run the risk of injury or being too tired to train.

What about the final six miles?

You might look at a training plan, see that it tops out at 20 miles for the long runs, for example, and wonder where you’re going to find the final six miles from on the big day.

This jump into the unknown is part of what makes marathon running so exciting. Yes, it will be hard, but remember that you will have tapered over the last few weeks of your training. (Tapering is when you gradually reduce the amount of training you do, so that you arrive on the start line feeling fresh.)

Also, during your peak training period, you will have been doing your long runs on tired legs, due to all the miles of running you’ll have done over the course of your build up. The extra difficulty of training for 20 miles on tired legs probably isn’t going to be equivalent to running 26 miles on fresh legs, for example, but it does mean that the jump might not feel as hard as you’d expect.

It’s not all about the long run

The marathon is an endurance event, but that doesn’t mean there is no place for speed in your training.

If you’re fairly new to running, or haven’t done any ‘speedwork’, even adding a handful of strides (short, sharp accelerations up to about 90% of your flat-out sprint effort) to the middle of one of your runs each week can help in a number of ways.

  • Increasing muscle strength
  • Improving coordination and running form
  • Getting used to running at different speeds
  • Providing some variety to break up the monotony of always running at the same, easy pace.

If faster running is new to you, and you’re trying to run a marathon for the first time, bear in mind that building your endurance is your first priority. Only add the faster running in if it’s not going to be detrimental to your longer runs.

If you’ve already completed a marathon and are looking to set a new personal best, or run a particular time, then speedwork can help you achieve that. After all, the best way to train to run faster, is to run faster.


Because a marathon is a long way to run, it requires a lot of energy. Understanding how your body uses this energy can help you prepare for the marathon challenge.

At the risk of over-simplifying a complex process, the body mostly uses two kinds of fuel when we run: Glycogen (from sugar and carbohydrates) and fat.

  • Glycogen is a “fast burning” fuel that gives us a lot of energy, but we can’t store much of it.
  • Fat is “slow burning”, so gives less “oomph”, but we can store loads of it.

What makes a marathon tricky, even compared to other long events such as a half marathon, is that for most people the amount of energy needed is more than we can store as glycogen. It varies, depending on the runner, but typically we can only store about 20 miles’ worth of glycogen.

This means we either have to:

  • Burn more fat towards the end of the race (which makes running feel harder); or
  • Try to top up our glycogen stores (by trying to eat when running).

For most runners, the right approach is somewhere in the middle:

  • Burn a bit of fat, and eat some sugar and carbs when running.

Your long runs will help with this, as they’ll get close to simulating the energy requirements of the marathon itself and are a chance for you to practice eating when running.

What to eat

Ask a room full of runners for the best marathon food and you’ll get loads of different answers. Popular options range from real food such as dates and bananas, through to energy gels and the classic jelly babies.

How much to eat also varies, but bear in mind that you’re going to struggle to eat enough while running to replace all your glycogen. Instead, think of it as regular top ups that will delay the point at which you hit empty.

Experiment during the early stages of your training plan until you find what works best for you. Then once you’ve got a favourite, stick with it throughout training so you get as comfortable with it as possible. You might find some food doesn’t agree with your gut at all when running, but hopefully the results won’t be too disastrous.


Eat something familiar the day before your marathon, with plenty of carbs in it. Where possible, avoid anything new, or that is likely to disagree with you. If you can, eat the same thing before some of your long runs. Drink regularly, too.

On the morning of the marathon, eat something you are used to that contains a mix of carbs and sugar. For example:

  • Toast with jam;
  • Bagels with hazelnut spread and a banana;
  • Porridge with maple syrup.

Find out what works best for you beforehand, so you have less to worry about on the day.


Over the course of your training, you’ll hopefully have begun to recognise how much you need to drink before, during and after your runs. Factors affecting this range from the personal (how much you sweat) through to the environmental (heat and humidity).

As well as replacing lost water, it is important to make sure you also replace the salts and electrolytes you’ll have sweated out, especially sodium. This can be done with drinks containing electrolytes, tabs that you pop into your drink, or through the food you eat.

A minor sodium deficiency can cause your muscles to cramp, which is unwelcome during a marathon. Very low sodium levels plus an excess of water can lead to hyponatremia (aka ‘overhydration’), which can cause serious health problems.

A rough rule of thumb is to drink little and often, when you feel thirsty, and make sure you include some sodium.

As with food, practice your drinking during training so that nothing is new on raceday.

Lonely Goats, Mel, Elly, Seb, Clare and Sam at the London Marathon
Our example runners

To illustrate how a beginner or an experienced runner might train, here are two fictional example runners:

  • Ian – who has just signed up for a marathon, but has no previous running experience.
  • Joy – who has run a couple of marathons and wants to set a personal best.

Using the principles outlined above, and taking into account the personal circumstances of each runner, here is how they could train to achieve their goals.

Ian, the beginner

The first step for Ian is, quite literally, to get out the door and start running. Couch to 5K is where Ian should begin. Once he’s done that, he should spend some time getting used to running regularly and enjoying it.

When half an hour of running is comfortable, it will feel like less of a jump to build to an hour of running – which is Ian’s next milestone. A 10K plan is an effective way of doing this.

It could take weeks to reach an hour of comfortable running, or months, but that’s OK. If anything, the longer Ian takes, the stronger his running foundations will be ahead of the jump up to pure marathon training.

Stepping up

Because this is Ian’s first marathon, hitting a certain time is not a priority. It is natural and understandable for him to wonder what might be possible, and even to have a goal in mind, but first he has to cover the distance. Therefore, extending the distance he can run is the aim of this training plan.

Many marathon training plans cover 3 to 4 months. This makes sense, as that balances having enough time to safely increase the distances run, without being too long that it is difficult to maintain focus.

This marathon-specific part of Ian’s training will take 18 weeks, as this allows him to increase his weekly long run by around 10 per cent each week. The ‘ten per cent rule’ (whereby runners limit their mileage increases to no more than ten per cent of the previous week) is not perfect – as all runners are different – but it’s a pretty good starting point.

In this way, with small increases each week, Ian can build from one to three hours of running.

Ian is planning his long runs by duration, rather than distance because it better helps to keep track of the “training load”. After all, he could potentially run further on a flat route with nice weather, than he might on a hilly course with a headwind – even if the second run takes ten minutes longer.

All of these should be run at an ‘easy’ effort level – which is an effort where he could maintain a brief conversation.

The rest of the week

What about the other runs Ian will do each week?

Ian likes to do three runs a week. He’s got into a good routine and wants to stick with that, which is perfectly fine. To allow enough recovery between long runs, he’ll limit his two other runs each week to around an hour of easy running. That should be sufficient to keep his overall running fitness up without tipping him into ‘overtraining’ territory.

The long runs take a lot of mental energy, so he decides to add some variety to the other runs to keep them interesting, and doesn’t worry about hitting target paces. He might do one of the following occasionally:

  • A trail run – to get out in nature and enjoy a chance of scene;
  • Strides – breaking up an easy run with a handful of short sprints;
  • Hills – challenging himself to get to the top of a long hill (and remembering to enjoy the view at the top!).

Just as long as these aren’t so strenuous that they affect his long runs, by having fun in this way, Ian will work on his overall running fitness and continue to enjoy himself.

Ian could also include other running events during his plan. For example, a half marathon would slot in nicely as an alternative long run, perhaps a couple of months before the marathon.

The big day

There is a very real possibility that the jump in duration from Ian’s final, three hour, long run to the marathon will be considerable. It’s important to remember what was covered above: With a taper, the buzz of the event, and months of training behind him, Ian should be capable of reaching the finish.

Lonely Goat, Kenny Watt at the Loch Ness Marathon
Joy, the PB chaser

Joy has run two marathons previously. For the first, she followed a plan similar to Ian’s, as  her goal was just to finish. By the time she ran her second, she was a more experienced runner and included some speedwork in her training plan.

The combination of many more miles in her legs, plus some faster running, meant she was able to knock a big chunk of time off her personal best. Now, for her third marathon, she wants to get another PB.

Gradual, natural progression

At this level of marathon training – trying to improve upon previous performances – there’s a huge variety of approaches. That’s understandable, as it encompasses everyone from recreational runners through to élites. Because of this, it’s difficult to prescribe a training plan that covers all these bases.

Instead, here’s how runners who’ve already completed a marathon can devise their own training plan to try and achieve a personal best:

  • Take what was done before;
  • Identify what worked, and what didn’t;
  • Consider how the elements of the previous training plan can be improved upon.

Assuming the training plan for Joy’s previous marathon was broadly successful, it shouldn’t be necessary to radically overhaul it. Instead, changing it through gradual, natural progression can yield the extra fitness required to chase a personal best.

Long runs

Joy’s previous pre-marathon long runs ranged from 10 miles at the beginning of the plan to 20 miles twelve weeks later.

Since her last marathon, she’s reached a level where her long runs are usually around the 12 to 13 mile mark so she can start her long run build up slightly ahead of where she did last time. Because she’ll reach 20 miles a few weeks sooner than before, she can do three 20 mile long runs, rather than one. This will give her a little extra endurance.


Before her previous marathon, Joy followed a training plan that included an interval session once a week. The exact composition of these sessions varied, but they would typically resemble the following:

  • 5x 5 minutes hard (with 2 mins easy inbetween);
  • 8x 3 mins hard (2 mins easy);
  • 15x 1 min hard (1 min easy).

Seeing as the marathon is predominantly endurance based, Joy decides to progress these sessions by making them more endurance focused. The easiest way to do this is to add more reps. For example:

  • 6x 5 mins hard (2 mins easy);
  • 10x 3 mins hard (2 mins easy);
  • 20x 1 min hard (1 min easy).

Another way to boost the endurance aspect of an interval session is to reduce the length of the recoveries. It doesn’t matter which approach Joy chooses – and she could mix and match between the two for variety – but by making them ever-so-slightly harder than before, she should get ever-so-slightly quicker.

Tempo runs

Between her first and second marathons, Joy discovered the 80/20 training principle, which states that the best way to train for an endurance sport like running, is to do eighty per cent of your training at an easy effort, with only twenty per cent at a hard effort. The science suggests that this gives better results than doing all your running as hard as you can. Based on this, most of Joy’s runs are done at an easy effort.

However, Joy has now reached a point in her running where her target marathon pace is somewhere between her easy long run pace, and her fast interval pace.

To give her the best chance of improving her personal best, Joy recognises she’ll have to spend some time getting used to marathon pace – which will mean spending a chunk of her training in this middle zone between easy and hard.

To do so, she adapts one of her easy runs each week into a marathon-paced tempo run.

(NB: Tempo runs typically fall into the gap between easy and hard running, but should be considered as hard runs for the purposes of sticking to the 80/20 plan.)

Because these are new to Joy, she starts modestly, by doing the last ten minutes of one of her hour long easy runs at marathon pace. Over the course of her training plan, she progresses this further, by increasing the amount of time she spends at marathon pace, until it takes up the whole hour.

By adding something new to her training plan that she hasn’t done before, the new stimulus of tempo runs should yield positive results.

It’s OK to ease back

One thing Joy noted when evaluating her previous training was that she was very tired by the end of the plan, which she thinks negatively impacted upon her race-day performance.

She is reluctant to reduce her mileage, because she is generally injury free and feels she can handle the distances. Instead, to reduce her chances of feeling overtired and overtrained, she makes sure to include recovery weeks more often.

Last time, she reduced her training for one week in every six, which she suspects may not have been enough. This time, she plans to temporarily reduce her training every fourth week.

She has also decided to use a three week taper, rather than her previous two week taper.

Cross training

The best training for running is running. Generally, the more running you can do, the better you’ll get at it. However, that rule of thumb only works up to a point.

It is possible to run too much and injure yourself, or just get bored of it and lose your motivation. To avoid this, you might want to add cross training to your plan.

Anything that resembles running or works your body in a similar way is a good option. For example:

  • Cycling;
  • Swimming;
  • Rowing;
  • Elliptical machine; or
  • Long, brisk walks.

You can include higher intensity activities, but bear in mind that too much could start to negatively impact upon your running.

Lonely Goats, Sarah Barker-Noble and Jo Hughes at the Greater Manchester Marathon
Trust the process, but expect it to be hard

Whether you’re running a marathon for the first time, or trying to set a personal best, the chances are that it will be hard. It might not be difficult or painful for the whole thing, but there will almost certainly be moments when you are struggling and want to give up.

Your training plan exists to prepare you for this mental challenge, as well as the physical challenge.

What will get you to the finish line isn’t one particular training run that went well, but the combined effect of all those training runs – especially the ones where you struggled. Whatever your plan looks like, trust the process of training and remind yourself of everything you have achieved to that point.

It might seem hard to do so, but aim to view the marathon as the fun bit. It’s the reward after all those months of training.

If you can get through a whole training plan, what’s another few hours?

Enjoy it

Finishing a marathon is an incredible achievement. It is also something that can be prepared for in a practically infinite number of ways. How far you run in training, how fast, how often, or any other factor, is up to you.

Yes, there are some methods and training plans that are more likely to be successful than others, but every runner is different and there is more than one way to train for an event.

Perhaps the most important thing is that you enjoy it. The more you enjoy your running, the more likely you are to train successfully and achieve your marathon goals.

There is a large, friendly community of other Lonely Goats that you can ask for advice if you want to know the best way to train for a marathon. Check out our social media channels – Facebook, Instagram and Strava – and join the discussion.

The Lonely Goat running training series

Check out the rest in this series of training articles…

…plus our other articles on different aspects of running training.

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