How to train for a marathon? Full beginners guide here!

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Want to know some details (like how long a marathon is, or how long it will take for you to complete a marathon? See here)

Thinking of entering a marathon? Maybe your very first marathon? One very important thing is preparation!

Even if you have trained for a couple of years (hint: you don’t need to train for this! People often run with under 20 weeks of training!) the effect it’ll have on your body is huge and you won’t have felt anything like it before!

But is it worth doing a marathon? Definitely yes! Talk to others who have done a marathon – many of them continue to do many more! Of course some will also claim that it was the most taxing thing they’ve ever done to their body and wouldn’t ever repeat it!


So, you want to enter a marathon…

Check your health! Get to a medical professional, and get checked over. A 26 mile run is a huge thing to do to your body. Don’t skip this! Even if you have been running 5k or 10k races for years, it doesn’t mean you body can endure a ~4 hour run spread over 26 miles!

Don’t go straight into a marathon! Obviously this article is about training, which will cover this point. But be sure to enter 10k races, half marathon races. Get a feel for it before the big 26 mile day!

You can do it with under 20 weeks of training. But more is obviously better! If you have the option between doing a marathon in 6 months or in 1 year and 6 months, obviously the 1 year 6 months option will give you much much more time to train and get your body accustomed to running longer distances!


Stay consistent, be committed! You need to be running 20-30 miles (approx 30-50km) a week (spread over several runs!). This is quite a big time commitment, and if you are training over winter months it can mean running through some quite horrible weather.

Find a marathon to enter. Each marathon has its own rules, costs, and of course its own location. You might have one that is right on your doorstep (one that literally runs along your street), or you might have to visit another city. You can also turn it into a mini vacation/holiday. But be warned, you will not want to go sightseeing or do any walking for a couple of days after the big run!

Running at home:

  • You know the streets
  • You are in your own surroundings, comfortable, maybe more friends and family will come out to support you

Running in a new city:

  • 100 times more exciting (in my opinion) to run in new city that you’ve never visited – which can be really motivating
  • But you don’t know the surroundings, won’t be familiar with the course.

The 6 important things to focus on when training for a marathon:

  • Rest! This is super important. Your body needs time to rest. Don’t go all-out one day, and expect to be able to go all-out the next day on another intensive run! Even if you can physically do it, you are just opening yourself up to the chance of injury.
  • Nutrition! You have to eat the calories! A training run can easily use up 1000 calories or more! This means you really need to start eating a lot more food every single day!
  • Regular, easy pace running! This will make up the bulk of your training days. A good, easy pace, to get the mile count up.
  • Speed runs – Interval training, HIIT, etc – aimed to increase your aerobic ability
  • Longer runs! Once a week (approx) you should go for a longer run. This will be a lot more taxing on your body.
  • Cross training (doing other exercises/sports)! Doing other sports (such as hiking, cycling, weight training) helps with your running ability (even if it doesn’t seem so directly related. For example, doing yoga has positive effects on your running ability)

Rest and recovery

This aspect of training cannot be ignored! If you train too much, too quickly you run a much higher risk of injury!

You need rest days, where you don’t run and/or exercise your legs! If you get injured, you can’t run in your marathon!

Of course, running is addictive and you might find yourself feeling like you just want to put your running trainers on and go out again. But you have to rest your legs! You can always do other forms of exercise (see cross training section below).

How often to rest?

You should have at least 1 full day of rest (no running) every 7 or so days.

How often to rest when the race is near?

When talking to other runners, you might hear about how they taper their training when approaching race day. For the last two or so weeks before the big race you should really rest a lot more than usual. See details about tapering for a marathon race here.


Normal nutrition (your breakfast/lunch/dinner meals)

Running uses up a huge amount of calories – especially the type of long runs that are required for training for a marathon! You need to make sure you eat enough every single day.

If you track your running progress with your phone (on Strava for example) you will get a (approximate) calculation of how many calories each run used. Our section on nutrition will be useful too. Make sure you eat enough!

Nutrition while running

It is common for marathon runners to effectively run out of juice at around mile 20 (known as ‘bonking’ or ‘hitting the wall’). After a few hours of using up all the energy in your body, you just don’t have any more glycogen in your body to convert into energy. You need to be sure you replenish this source.

On short runs (approx under 1 or 2 hours) you probably won’t have to worry about refuelling mid-run. But for longer runs you’ll need to have something to eat or drink and replenish your energy supply. There are many types of energy foods (gels, drinks, energy bars, etc).

You should aim for around 60 grams of carbs per hour on longer runs.


Making sure you have enough water (both in your body, and what you are carrying or have access to) it critical when you are running!

There are a wide range of options when it comes to things like a hydration pack, camelbak, belt, or even just carrying a water bottle with you. On the actual marathon race day you’ll find many water stations where you can pick up something to drink mid-race. But of course for the months of training this isn’t an option so get a system that works for you.

Regular running

This will make up the bulk of your weekly milage. You should be able (by the end of your training) to run 50+ miles a week, spread over several runs. You should ideally aim for around 4 or 5 days of running, with at least one rest day every 7 days or so. This means a lot of hours spent out running every week.

These regular runs should be at an easy to maintain pace – nothing too taxing. You just need to get your endurance up.

I personally find a super early sunrise run (and then going back to bed after) or a night time run works best for me. If I run in the middle of the day I am just worn out for the rest of the day and not really productive. But you have to find what works for you!

Speed Work

Some might argue that speed work isn’t crucial to add to your first marathon training schedule, but it can help. You should do short bursts of high effort runs.

They can be things like intervals, where you might run 1 km at a very fast pace, then walk (or light jog) for a couple of minutes, and repeat. These will be very tiring, but they help increase your aerobic capacity.

You can also do tempo runs which are similar to intervals but longer. In intervals you are going almost all-out. In tempo runs you might run 5km at a quite fast pace.

Longer runs

  • Every week or so you should do a longer run.
  • Every week your long run should get longer and longer.
  • But – every few weeks you should take a week off and have a chilled out week!

These long runs will be at a much slower pace than your regular runs.

Cross training

It is a good idea to train your whole body.

Get active in non-running exercises. This can be anything from biking, weight training, yoga, and more. It can give your legs a rest from running, while improving your general fitness elsewhere in the body.

But never forget these two important things that aren’t in the list above:

Warmups and warm-downs. Yes they can feel like waste of time, but wait until you get an injury and you’ll wish you spent 5 – 7 minutes at the start and end of each run or workout.

Race Day Tips

So, after weeks and weeks (more like months and months) of training, the big day is here. The 26 mile race!

  • Make sure you are prepared for the race. Don’t try new clothes, new running shoes, etc. Make sure you’ve spent the last couple of weeks breaking in any new items (especially new race trainers).
  • Drink well in the days before the race. Make sure you are hydrated before the race begins.
  • Don’t forget about vaseline in areas that tend to chaf.
  • Go to the port-a-potty line early  – the queues can be long!
  • Remember to start slow. Don’t get caught in the moment and start running too fast!

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