Running the London Marathon without training could be possible, experts reveal

Running a marathon is, without question, one of the single greatest feats of human endurance.

Athletes face aching muscles, dehydration, cramps and chafing as they push their body to its limits. Although incredibly rare, some runners have even died from the sheer exertion.

That’s why entrants for London‘s prestigious event, now just two days away, spend months painstakingly preparing their body and mind for the mammoth task ahead. 

However, not everyone commits to such a meticulous training plan.

Brave, or stupid, runners claim to have miraculously completed the 26.2 mile route without any prep at all.

Irish pop singers Jedward (John and Edward Grimes) reached the finish line of the LA Marathon in 2012 in little over four hours, and afterwards famously claimed that they never bothered training beforehand.

The former London Marathon race director, David Bedford, apparently only signed up to run the 1981 race hours before the event, while he was in a nightclub. 

Although Mr Bedford — on a stomach full of curry — completed the course, he was filmed throwing up midway. He later joked that ‘everything ended up on the track’.

On the other hand, TOWIE star James Argent lost roughly 3st during an intense six-week training regime ahead of the 2012 London Marathon.

Jedward (John and Edward Grimes) ran the Los Angeles Marathon in 2012 on a whim after stepping of a flight without any training (pictured left). It took TOWIE’s James Argent six hours to finish the London Marathon in 2012 and he was surprised at how much pain he was in following the run (pictured right)

Comedian Eddie Izzard ran 43 marathons in the space of 51 days in 2009 after only five weeks of training.

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It took him just over six hours to finish and he was surprised at how much pain he was in following the run, forcing him to cancel his post-marathon clubbing plans.

Meanwhile, comedian Eddie Izzard did five weeks of training before embarking on his marathon in 2009. Yet he wasn’t content with finishing just one — and ended up doing 43 of them in the space of 51 days. 

But is it wise, or downright stupid to put your body through the exhausting challenge without stepping foot on a treadmill beforehand? 

With runners limbering up for Sunday’s London Marathon, MailOnline asked sports and exercise experts for their advice.

According to Professor Kieran Clarke, an expert in diet and physical performance in athletes at the University of Oxford, it is entirely possible to run a marathon without training. 

But there is one huge caveat; you would need to be physically fit.

Using the example of an Olympic rower, she said: ‘Somebody who is an athlete who is used to endurance exercise will probably be fine. 

‘They might cause a little bit of damage to their muscles.

‘But if they are used to doing endurance exercise often, they can switch from one form of exercise to another without any problem.’

This may be why Jedward raced to success in the LA marathon — the twins used to represent Ireland in cross-country running competitions.

Professor Kieran Clarke, an expert in diet and physical performance in athletes at the University of Oxford, suggested that someone who is physically fit from work could run a marathon without training 

However, it is a wildly different story for those who do not exercise at all.

‘For somebody who is sedentary, it would be a total disaster,’ Professor Clarke added. 

‘First of all, they could tear muscles, they could overheat, and they could end up just collapsing.

‘Everything that prepares you for exercise just wouldn’t be working. They probably would not be able to complete the first mile.’

Professor Clarke, who has been involved in the field of exercise for decades, suggested that someone who is physically fit from work could run a marathon, however.

She added: ‘They would probably have to run several times a week, they would have to be able to run at least a couple of miles without getting puffed.

‘Some young people could probably do it, with a few weeks of preparation, depending on how healthy and fit they are and what other exercise they do.’   

Dr Darren Player, a lecturer in musculoskeletal bioengineering at University College London (UCL) and a qualified personal trainer, recommends at least 16 weeks of training before running a marathon.

He is the co-author of a book called ‘LA ULTRA: cOuch to 5, 11 22 km in 100 days’, which, like Joe Wicks, helps people with practical recommendations on how to go from a sedentary lifestyle towards building running into their lifestyle. 

He suggests people should work up to a marathon by first training for a 5K, roughly one eighth of a marathon.

After that, they should steadily increase their distance over three months, in a similar fashion to those seeking to complete exposure therapy to overcome a phobia. 

Running long distances without prior training increases the risk of injury. Common sites of injury for runners include the lower back, ankles, knees and feet according to Dr Player. The UCL lecturer advises new runners to speak with a personal trainer or even a GP before taking on the challenge of running a marathon

He said: ‘You would have to be an extremely well-trained individual to be able to complete a marathon without any specific training.

‘One of the first basic principles of sport science is specificity, you have to be training for the particular sport you are going to undertake. 

‘A marathon is quite specific in terms of the distance, duration, and the level of fitness that is required.

‘Even if you were a highly trained cyclist, you might just be able to tolerate a marathon, but it would probably still be very difficult.’

Muscles have to become efficient at oxidising fat as a fuel source, according to Dr Player. And if this does not happen, fatigue could set in early.

Once the body has burned through the quick sources of fuel available to it during the marathon — carbohydrates which are stored in the muscles as glycogen — it has no choice but to turn to fat.

Although there is a plethora of health benefits from running, including better lung function and blood flow, and improvements in mood and anxiety, there are obvious downsides, too. 

Even if you did have the motivation to complete the gruelling task, experts warn you would be more at risk of injury if you didn’t bother training. 

Athletes put in months of training to be able to withstand running 26.2 miles without collapsing. Thousands of runners take part in the London Marathon each year, in 2019 nearly 43 thousand runners participated in the prestigious event

Ankle, knee, lower back and foot injuries are all common sites of injury if you have not built up that tolerance from repeatedly hitting the ground. 

In extremely rare cases, sudden cardiac death can occur. Cardiac arrest is when the organ’s electrical activity completely shuts down, unlike a heart attack — which is when an artery that sends blood and oxygen to the heart is blocked.

Extended vigorous exercise can put your heart under stress, drastically raising the rate at which it pumps blood out. 

It can stop pumping if it’s too overworked, in theory.

Coupled with hot weather conditions or any undiagnosed cardiac issues, this can potentially have grave consequences — especially for the underprepared. 

Dr Player added: ‘I would always advise if someone is going from a completely sedentary lifestyle to just take things very slowly and even consult with a GP about their current health to see if they are safe to be undertaking that form of training.’  

If you want to finish a marathon and walk away injury free, then you absolutely need to train beforehand and adapt your diet, advises David Wiener, London based training and nutrition specialist.

Mr Wiener said: ‘You simply can’t run 26.2 miles without training or having any running experience. 

‘If you are planning to run a marathon, I would recommend starting training at around 20 weeks before the race.

‘Training for a marathon doesn’t just include running, you need to have a good nutrition plan, and compliment regular running with strength training to ensure your body is in peak physical condition and that you have the stamina to run and finish the race.’

It is recommended to eat plenty of carbohydrates in the run up to race day to avoid hitting an energy wall. When you eat carbohydrates your body stores it as glycogen, a form of energy, in your muscles and liver

Most runners prepare for a marathon by fueling up on carbs and eating pasta, rice and potatoes the night before to give their body a one up. 

Internally, the body turns the carbs in the food into glycogen, a form of energy, and stores it in the muscles and liver. 

During a marathon your body will burn both glycogen and fat, but fat is harder for your body to convert into fuel. That’s where the back-up carbs come in handy. 

For the same reason, this is why runners often can be seen consuming energy gels and drinks both before and during a race. 

Mr Wiener added: ‘Your heart, muscles, stamina, stomach and mind all need to be prepared before a marathon, and it’s extremely dangerous to start the race without doing so or properly preparing. 

‘Of course, everyone is different and your training and nutrition plans should reflect this. Before taking on a marathon, I would also recommend seeking expert advice and having a health check.’ 

Mr Wiener, of AI-based fitness and lifestyle coaching app Freeletics, recommends running regularly and incorporating strength training and high intensity interval training (HIIT) to improve your endurance. 

Exercise experts recommend a mix of strength training, high intensity interval training and low impact training such as yoga and Pilates alongside running to properly prepare for race day

Mr Wiener said: ‘The only way to work on your running skills is to actually run. If your legs aren’t used to running, all a marathon will do is injure and strain your muscles, ligaments, and joints — all at the same time. 

‘Start off slow, and each week aim for personal bests and hit longer distances. Once you have completed a half-marathon, this is when it’s time to prepare for a full marathon.’ 

He added that recovery and low impact training, such as walking, Pilates and yoga, is also worth secluding into your marathon training.

Some celebrities entering the London Marathon this year already seem to be putting in the arduous training required.

McFly drummer and 2011 Strictly Come Dancing winner, Harry Judd, has posted his training pictures and fundraising efforts for The Children’s Trust on Instagram.

Helen Thorn, comedian and co-host of podcast ‘Scummy Mummies’, is also taking on the challenge this year and raising money for single mums. She has been posting her running routes and fitness progress over the weeks leading up to race day.

However, some famous faces are more prepared than others as BBC Two’s Race Across the World winner, Emon Choudhury, has been training for the marathon and recently took part in the Bradford 10K.