How to run your first marathon
Running your first marathon is an event that you'll remember for the rest of your life. Here's all you need to know to confidently conquer your first-ever marathon...
Running your first marathon can be an exciting yet daunting challenge. Where to start is probably the first thought that comes to mind. There’s a lot that goes into marathon training – from weekly runs, to nutrition, recovery, and everything in between.
With the right training and a race plan in place, you’ll have all the building blocks needed to smash your first-ever marathon. In this article, we’ve broken down the key elements you’ll need to incorporate into your training and racing to have a successful, and dare we say enjoyable, race. Let’s get into it…
How do you run a marathon for the first time?
You should be coming to marathon training with some running experience under your belt. Even if that translates to cross country back at school all those years ago. Before officially setting out on your marathon journey, try to get to a place where you can run 10km, or for one hour, non-stop and fairly comfortably.
Set a training schedule
Your marathon training plan should give you plenty of time to slowly build your run fitness to a level where you can run comfortably for hours at a time. The key here is consistency and endurance, whether you choose to train on heart rate, pace, or effort, time on feet is what’s going to prepare you for the long-distance effort that is the marathon.
Consider finding a coach or using a running app to help structure your training. There are also plenty of training plans online, but the basic formula is the same. As a rough guide, each week, you should try to incorporate an interval or hill rep run, a tempo run where you practice race pace, an easy shake-out, and a long run (more on this below).
It depends on you, your availability, and other cross-training you’re including in your training, but you should aim to run 3-5 times per week. The initial first four weeks of training should slowly ease you into regular, easy runs. Then, look to include build blocks into your training where you gradually build in distance and intensity.
Don’t skimp on recovery and rest days, though, and be sure to include ‘de-load’ weeks every few weeks where you take the foot off the gas and give your body time to catch up and adapt to your training.
Don’t skimp on the long run
The long run is one of the more important aspects of a marathon training plan. Each week (probably at the weekend), look to complete a ‘long run’ into your training schedule. This run should be completed at an easy, talking pace. In other words, the long run should be done in a ‘steady state’ or aerobically.
Your long run may start at 10km, if that’s the maximum distance you’re used to running. From there, slowly build in distance by no more than 10% per week, with your de-load weeks also dialing back the distance for the long run, too.
It might sound frustrating to build in distance so gently, but this is really key to avoiding injury from going too hard, too soon. Hence the importance of setting aside plenty of time to train.
For example, your first four weeks of marathon training may see you run a long run of 10km, then 11km, 12km, and 13km per week. The initial build feels slow, but as you increase the distance, 10% will also equal a larger distance increase. Be patient, and enjoy the ride.
Recovery is king
Looking after yourself and your body is essential if you want to get through marathon training and stand on that start line in one piece. Your marathon training plan should include both active and full rest days.
Active rest days are when you have the option to do some light activity like walking or gentle swimming, while full rest days are what they say on the tin, time to put your feet up and relax.
Active rest can help to unwind tight muscles, build some strength, and improve mobility. Just be sure not to go too hard during these sessions as they’re really about having a break from marathon training and enjoying other movements.
You can maximise the benefits of your full rest days by ensuring you eat nutritious, protein-packed meals and get plenty of sleep. Your muscles need time to adapt and become stronger from your training, this time is key to help avoid injury and reap the full benefits of your training plan come race day.
Remember your goal
When you decide to take on the challenge of running your first marathon, it’s useful to have a goal in mind. This will help to guide your training progression and give you motivation when it comes to race day.
Your marathon goal may be a time goal – perhaps you’re aiming to finish under five hours, or four – or perhaps your goal is simply to complete the marathon without walking. Whatever your goal is, be sure to consider it when you’re planning your training and race-day strategy.
There’s no point following a training plan for a sub-3 marathon if your aim is to finish within the cut-off time. To accurately understand what a realistic marathon time looks like for you, why not complete a 10km time trial (as fast as you can) and use this to estimate an aspirational, yet realistic, marathon time after 20 weeks of training under your belt.
Nutrition strategy
Nutrition during marathon training doesn’t need to be technical (unless that’s something you’re after), or leave you having to cut out any foods. Like with many things in life, nutrition is all about balance.
As you get into exercising more regularly and build up in training, it’s likely that you’ll naturally start reaching more for foods that the body needs. This is called intuitive eating. However, if you can be swayed by a sweet craving, or are too keen on crisps, then it’s a good idea to keep an eye on indulgences, allowing them in moderation.
Eating a healthy diet will help you reap the full benefits of your training, providing your body with the building blocks from the inside to produce enough energy for running and to recover afterward.
As a general rule, you should aim to fuel with slow-releasing carbohydrates, like wholemeal pasta, bread, oats, and potatoes, ahead of a long-run and incorporate these into your breakfast (porridge is a winner).
Meanwhile, during a run you’ll want more readily-available energy in the form of fast-releasing carbs that are found in the best energy gels. Equally, your meal after your session should be packed with protein to aid recovery, as well as other good stuff like vegetables, minerals, and nutrients, of course.
If it’s unrealistic to be sitting down for a meal within the first 30 minutes of a hard or long training session, then consider keeping protein-rich snacks on hand such as a protein drink or protein bar.
How long does it take to train for a marathon?
Typically, you should start your marathon training at least 16-20 weeks ahead of your target race. Especially for beginners, it’s key to set aside enough time to ease yourself into marathon training and slowly build up a training base.
If you already have a few half-marathon races ticked off and are used to running for 1.5-2h during your long run, then you can consider shortening this build time to 12 weeks.
Three months would be a minimum amount of time that we’d recommend to give yourself the time to slowly build distance and taper a couple of weeks leading up to the race.
How to master the run leg of an Iron-distance triathlon
Training to run your first marathon and training for an Iron-distance race will look considerably different. For the marathon, you’ll be focussing mainly on running, strength, and recovery. Whereas, an Ironman will require adequate bike and swim training sessions built in.
Structuring your training for an Ironman is particularly important, because your aim is to be able to complete the event without getting injured or burnt out. You should be running around three times per week as a minimum, and include within this an interval run and a long run to build the mileage.
The key difference between single sport and Ironman training for the run leg is getting your body used to training in a fatigued state. During training, this translates to brick workouts and back-to-back long run days.
What is a reasonable time for a first marathon?
For your first marathon, the main goal is always to finish and bask in the achievement of simply having completed the challenge. This gives you the freedom to run at whatever pace you like.
However, if you’re someone who’s interested in time goals and what a realistic estimate would be of your first marathon time, then you’ll need to take a step back and consider your current run pace and 10km or half-marathon time.
Aside from meeting the cut-off time, which for the 2024 London Marathon was eight hours, there is no unreasonable time to complete your first marathon in. You are free to job, walk sections, and run at whatever speed feels right for you and your goals.
For your first marathon, expect a time between four and six hours to complete the whole distance. For faster runners, under four hours would be reasonable, whereas other runners may find themselves taking longer than five hours.
If you want a more precise estimate of what your time would reasonably be, use a pace calculator and your most recent race result to estimate how long it may take you. Your marathon time depends highly on your current running fitness and endurance capabilities, which you can then build on during training.
What is the 10-10-10 rule for marathons?
The 10-10-10 rule is a pacing strategy for marathons that outlines that the first 10 miles (16km) should be completed at five seconds slower than race pace, the second 10 miles should be at race pace, and the last 10km should be either at race pace or faster. This gives the body time to slowly build up and warm up to the race.
Looking for your next challenge? Why not check out our complete guide to how to run your first ultramarathon.
Kate Milsom
Freelance sports journalist 
