Taking the leap from completing a half-marathon to a full marathon is one of the most rewarding challenges a runner can take on. While the 13.1-mile distance is a major achievement in itself, doubling it requires more than just physical endurance. Knowing if you’re ready to take on this challenge and being aware of the mental resilience needed, as well as creating a structured training plan, is the key to success. Whether you're aiming to achieve a new personal milestone or simply curious about testing your limits, knowing when and how to make the jump is vital to a successful transition.
Every runner’s journey is unique, which is why we are here to help you assess your current fitness level and identify the signs that you’re ready to step up. From recognising the right timing to adjusting your training and mindset, we’ll walk you through everything you need to know before committing to 26.2 miles and becoming a marathon finisher with confidence.
How long does it take to train from a half marathon to a full marathon?
If you’ve recently completed a half marathon then congratulations, you’re already halfway to conquering the full 26.2-mile marathon distance! But going from 13.1 miles to 26.2 requires a lot of training in order to do it safely and in good time. The length of time it takes to train for a full marathon will vary person to person, and will depend on your current fitness levels and running base.
Moving from a half marathon to a full marathon will typically require between 8 and 16 weeks of training. If you’re a consistent runner (this means you’re running about 20-30 miles per week) then you should have a solid aerobic base, and an 8-12 week training period should be sufficient. However, if you took some time off running post-half-marathon, or you don’t clock up that many miles per week, you may want to try a 12-16 week plan to help build up endurance without risking injury.
Additionally, if you’re running the marathon simply to just complete the race, and you don’t have a specific time in mind, then a shorter training plan may suffice. However, if your goal is to beat personal best times and work on pacing, a longer training plan will help you include tempo runs and speed work to improve pace.
Keep in mind that, regardless of your goal, the most important part of marathon training is the length of the run. Therefore, during training, you should aim to gradually increase your long run every 1–2 weeks, building up to 20–22 miles before your taper. These long runs are essential not just for testing your physical endurance, but also for learning fueling strategies, pacing, and building up mental stamina.
Half-marathon to marathon training plan
If you’re eyeing up the full 26.2 mile challenge, and you're wondering how to get there without burning out or getting injured, following our 16 week training plan is the best way to help you build on your current fitness. Designed to gradually increase your mileage and confidence with long distance running, this plan will help you reach full marathon potential easily. Sticking to a weekly training schedule is key to keeping your base fitness level up and staying consistent with your progress. We suggest running 3-4 times per week:
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Run 1: An easy run at a conversational pace
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Run 2: A slightly longer run to build endurance
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Run 3: A longer run to increase mileage
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Run 4 (optional): A short, easy-paced recovery run
Make sure that on rest days you’re still keeping active in some way, whether that be with walking, cycling, yoga or other low-impact physical activities. Remember to listen to your body, and know that it’s okay to rest and skip a run if needed. Investing in the right gear like proper running shoes fitted to your gait, breathable activewear and a reliable fitness tracker will also ensure you stay on track with your training.
What is the 10-10-10 rule for marathons?
When it comes to training for a marathon, learning how to pace yourself correctly is the most important element to not overexerting yourself and completing the race in good time. The 10-10-10 rule is the most popular pacing strategy for marathons. This rule divides the race into three segments: the first 10 miles, the next 10 miles, and the final 10 kilometres (6.2 miles). Following this rule is the best way to manage your energy levels and avoid "hitting the wall" by running too fast in the initial miles.
The 10-10-10 rule:
Encouraging you to start the marathon at a comfortable pace, building up to a steady pace, and then pushing hard in the final 10k, below is a breakdown of what to focus on at each stage.
First 10 miles
For the first 10 miles of your race, the aim is to run easy, holding back your pace to try and conserve as much energy as possible for the rest of the race. At this stage, it’s important to stay relaxed and in control of your pace and breathing.
Next 10 miles
At the second stage, it's time to pick up the pace, ideally settling into your goal marathon pace. It’s important to stay steady and efficient, gradually building momentum and pushing your effort.
Final 10 kilometres (6.2 miles)
This is where the real race begins in the marathon. If you have the energy to, this is your chance to give it your all. Run at maximum effort, push through fatigue and give it your best so you can finish strong.
Although this method is not a rigid formula, it is a particularly useful mindset to take on for less experienced marathoners or those who tend to go out too fast, as it helps to break the long race down into manageable chunks, to prevent early burnout and end on a high note.
Get ready for your next race with Start Fitness
If you’re feeling inspired to start training for your next race, and finally complete a full marathon, we're here to ensure you have all the right equipment you need to succeed. Browse through our full running collection to find everything you need to look and feel your best whilst training and on the big day.