How to train for a marathon
From pacing your runs to fuelling up, here’s an expert guide on how to train for a marathon
You’ve signed up for a marathon — now it’s time to work out how to train for a marathon. The good thing is you’re not alone with over one million runners completing a marathon every year according to the International Institute for Race Medicine. All this first-hand experience has led to a plethora of marathon training know-how, but where do you start?
Before you head off on that first training run it’s worth doing a quick inventory. Grabbing one of the best running watches is a good starting point, as these tracker help you monitor your metrics. We’d also recommend gearing up with the proper kit, ensuring you’ve got a reliable water bottle and one of the best sports bras for running too.
But according to Lillie Bleasdale, Founder & Head Coach at online run coaching platform PASSA, the one thing you absolutely need before heading into training for a marathon is the correct footwear. “The right shoes for your gait are really important to help ensure you avoid injury throughout your training,” says Bleasdale.
Make sure you understand how running shoes should fit before you splash out on a new pair – we'd recommend going into a sportswear store that offers a dedicated fitting service before you buy.
As for the actual training, well, we’ve got you covered with this comprehensive and actionable guide on how to train for a marathon.
How long should a marathon training plan be?
This really depends on your goal, according to Bleasdale, as well as pre-existing fitness levels and personal circumstances, with most runners taking between 16 and 20 weeks to train for a marathon.
A successful training plan will mainly be predicated on fitting enough sessions in to get your fitness level up, while also ensuring you give yourself enough time to recover well and rest.
How often should you run?
With this in mind, you should target however many runs a week is doable in your situation, says Bleasdale. “For some people, this may be one to two, for others this may be five or six. If training for a marathon, I'd suggest a minimum of three runs per week, building to four or five in the later stages of the plan.”
These runs through the week should vary in both distance and effort. “You want to ensure you are working through a mixture of sessions in your marathon training. The key run of the week is going to be the long run when we're gradually increasing time on feet. Before the marathon you're looking for your longest run to be 18-22 miles, although studies show that longer than three hours can be detrimental to improving fitness in comparison to injury risk.”
Tempo runs and pacing yourself
This takes us on to the speed you should be running at, which again depends on your aim.
“If speed is your goal, then you certainly want to be including one to two interval or tempo sessions per week,” says Bleasdale. A tempo run is a moderate-to-hard intensity training run and is usually referred to as your 10k pace, while interval training involves alternating between short bursts of running at your fastest, with longer intervals of jogging, walking, or running at a slower, steadier pace.
“If you're short on time, then integrating some longer tempo work into your long runs can be a good way to manage this [training for speed] but on a less regular basis,” says Bleasdale. “The bulk of your mileage though is going to be lower heart rate, lower effort, relaxed miles.”
Build your marathon training plan
Using all of the above regarding how often you should run and the intensity, start to plot your runs on a 16-week schedule according to your personal timetable. If you’re a complete running newbie, start with a jog or a brisk walk in the first couple of sessions before edging into some interval training runs so as to build your fitness level up to a point where you can run a number of miles without stopping or needing a rest.
“Ideally you want to be running 4-5 times per week by the end of the plan,” says Bleasdale, “and building your mileage by no more than 10 percent per week.”
- Related: How to start running
Fuelling up while marathon training
Properly fuelling yourself before, during, and after your runs is vital when training. It's recommended runners add 100 calories to their regular daily caloric intake for every mile, with researchers from University of South Carolina Aiken measuring energy expenditure from running one mile to be around 115 calories.
The body’s preferred energy source for running is glucose, which is what your body breaks down carbohydrates in food into (carbs make up around 65 percent of our diet). Your body’s storage of glucose gets used up and begins to decrease as you’re running, and if not restored, will eventually run out.
There are a number of ways you can keep these stores stocked up. Firstly you could have a carb-filled breakfast, like porridge, although the added fiber here can cause digestion issues. You may choose to instead carb load the night before, and then run fasted the morning after.
A small shot of coffee before a run can also help, with The International Society of Sports Nutrition finding caffeine to consistently improve exercise performance when consumed in doses of 3–6 mg/kg body mass.
- Related: Best protein powders
While running you might want to think about carrying some sweets to stick to the side of your mouth for a small supply of glucose as you run.
Protein after a run will aid recovery between runs with The International Society of Sports Nutrition recommending protein intakes of 1.4–2.0 g/kg per day for physically active individuals.
The best way to fuel though is to simply decide what works for you through trial and error, and that’s why it’s important to keep your nutrition to what’s been tried and tested. “Practice your race day fuelling from day one,” says Bleasdale. “Make sure you don't leave this until race day.”
Should you be doing any other kind of exercise?
While training for a marathon is an intense and time-consuming undertaking, it’s important to keep up with other forms of exercise as well.
“If you are partial to some cross-training such as swimming or cycling then this is great to include as active recovery,” says Bleasdale. “I'd also strongly suggest including a level of resistance training at least one to two times per week to help with injury prevention.”
In fact, according to a systematic review from the Autonomous University of Madrid, undertaking a resistance training session up to three times a week has been shown to enhance running economy (oxygen and energy use) by two to eight percent, as well as improve time trial performance by around five percent. These might not sound like huge percentages, but the marginal gains will prove all-important in taking you from training for a marathon to actually getting over that finishing line.
- Related: Best resistance bands
Live Science newsletter
Stay up to date on the latest science news by signing up for our Essentials newsletter.
A former commissioning editor at men’s lifestyle site FashionBeans, and lifestyle writer at The Telegraph, Richard takes pride in his ability to craft engaging reads on pretty much any topic imaginable. He is currently editor of inForm, the in-house magazine of supplements brand Form Nutrition, and specialises in easy-to-follow guides within the health and fitness space. Along with these roles, Richard also has bylines with The Evening Standard and The Independent.