Get 26.2-mile fit in four simple steps with this painless plan.

“The great suburban Everest” is how London Marathon co-founder Mr Chris Brasher eloquently captured the lure of the race. A benchmark, bucket-list feat of endurance, yet accessible and achievable for anyone ready to hatch a grand plan over a drink or two and knuckle down to some training once the morning-after haze has lifted.

As a glance at social media or an ear at the water cooler will tell you, a lot of people run marathons these days, but just as Everest hasn’t got any lower, the marathon hasn’t got any shorter. So if you want to stride over that finish line, you’ll need to train. And if you want to do so in a decent time, enjoy the experience and not spend the next week hobbling around like a rodeo rider after a bad day at the office, you’ll need to train smart.

Do it right and the 16 weeks you should spend prepping for your 26.2 will be hugely rewarding, as your fitness skyrockets and your stress levels plummet, your body tautens and your mind sharpens.

Here’s what you need to know to get to base camp in peak condition, and enjoy every step of the way.

It seems counterintuitive, but the best way to prepare your body for running a lot of reasonably slow miles is not simply running a lot of reasonably slow miles. You need to change gear. Running at different paces trains different bodily energy systems, types of muscle fibres and aspects of your fitness. It’ll transform you into a stronger, more biomechanically efficient runner and keep your mind engaged, making the whole process far more enjoyable. There’s nothing fun about plodding for hours on end.

While there are almost infinite permutations of the finer detail, you can keep it simple with three pillars of marathon training: firstly, long runs, which are typically weekend outings at an easy, conversational pace, building by a mile or two each week and peaking at around 20 miles. Secondly, “tempo” runs, which are shorter, at a sustained “comfortably hard” pace. And then interval sessions – aka speed work – which involve short, fast bursts interspersed with recovery periods of either total rest or slow jogging.

Then, if you’re so inclined, there are hills. Described by Olympic marathon champion Mr Frank Shorter as “speed work in disguise”, incorporating hills via hard-up, easy-down interval sessions, or by choosing hilly routes for your tempo or long runs builds extra strength, power and efficiency which will pay dividends in the tough final miles on race day.

Do each of the three key sessions once a week, on non-consecutive days, with total rest, or short, slow recovery runs or low-impact cross-training (elliptical trainer, bike, swimming) on the days in between.

Plug a recent time from a race or time-trial into a race time predictor such as this one to set a realistic target marathon finish time, which you can use to calculate target paces for your sessions. And get a full training plan tailored to your goal here.

As the weeks tick by and you clock up the miles, recovering for your next session and staying a step ahead of injuries becomes as important as the running itself. Start with a few minutes stretching key muscles – quads, hamstrings, calves – immediately after running, and grit your teeth for some foam roller work on tight spots later.

Hitting the gym on non-running days helps, too. Targeted strength work counteracts both the injury-inducing effects of our desk-bound hours and the repetitive motion and impact stresses of running, strengthening weak links and ensuring joints move through their full range of motion. Include planks, side planks, lunges, clamshells and glute bridges, squats and single-leg squats.

You’ll also need to flex your mental muscle to get out on days when the weight of cumulative fatigue pins you to the sofa, the rain’s pelting down and you hear the siren call of a glass of something red and alcoholic. You’ll need grit to power through the hard yards of your interval sessions, or the double-digit mileage of long runs. But as well as strong, you’ll need to be supple of mind. When you feel a niggle in your calf or a tickle in your chest, you must be ready to adapt your plans and skip a run, or two, to let your body recover. Many would-be marathoners are derailed by full-blown injuries because of their obsession with completing every minute and every metre of every session on their training plan. Any coach worth his electrolytes will tell you that a few extra rest days over 16 weeks won’t harm your chances of making the finish line, but it could significantly raise your chances of making the start line.

And when your diary permits it, get an early night: recent research found reduced sleep hours was the number one predictor of injuries.

The more miles you run, the more it’s worth investing in high-quality running apparel. It doesn’t just set you apart from pack sartorially, it’ll ensure you enjoy your miles more and perform better. Technical fabrics “breathe” and wick away sweat, regulating body temperature and minimising chafing, while protecting you from the whims of the weather gods.

As for running shoes, tune out the jargon and go for what feels right. Research by leading biomechanist Dr Benno Nigg, author of Biomechanics Of Sports Shoes, found that when runners choose the shoes they find most comfortable, they run more efficiently and have fewer injuries. As you run, consider whether your shoes support your arch, don’t slide off your heel and are roomy enough that you don’t bang your toes at the front. Going half or even a full size up from your everyday shoes can save you a painful black toenail. Oh, and an excellent excuse for sneakerheads to indulge – research shows that rotating several different pairs can reduce injury.

You should also invest in a bit of gadgetry. A GPS-enabled sports watch gives you invaluable real-time info on pace and distance as you run, and post-run it’ll connect to training apps and platforms such as Nike+ Run Club or Strava to log, analyse and share your sessions.

For runs of less than 60 minutes, just take water. If you’re going longer, supplement with 30-60g of carbs per hour from sports drinks or gels. This ensures you don’t empty your body’s store of readily available energy, glycogen, so you’ll finish strong and recover quicker. It also trains your body to absorb and use these on-the-run energy sources better in preparation for marathon day; and gives you the chance to try different formats, brands and flavours to see which work best for your digestive system and taste buds. It’s fair to say none of these products will be winning any Michelin stars, but you don’t want to be experimenting on the big day or else something might disagree with you and ruin your race.

Post-run, rehydrate and take in some easily digested protein in that crucial 30-minute window when your body is most receptive.

In your general diet, as you will be torching a serious amount of calories, you can enjoy the dual pleasures of eating very well indeed and still watching any excess timber fall away. That said, you’re asking a lot of your body, so you need to make sure what you eat contains complex carbs for fuel (whole grain bread, starchy vegetables, brown rice, quinoa, sweet potato) protein to aid post-run recovery and fruit and vegetables for the vitamins and minerals you need to support your developing muscles and an immune system, which can be compromised by high mileage.

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