Image copyright Comic Relief

Eddie Izzard has completed 27 marathons in as many days for Sport Relief. But can his body recover from such a feat, ask Robert Spencer and Justin Parkinson.

The numbers are astonishing. In 27 days, Eddie Izzard ran or walked 707.4 miles (1,138 km) around South Africa, often in extreme heat, at the age of 54. On the last day, because of earlier disruption, he did a double marathon to ensure he reached his target.

The comedian's exertions for Sport Relief have raised more than £1.35m. But now, as the elation of completing his task recedes and he continues to deal with media interest in his achievement, Izzard must begin his recovery.

"I can't stand upright," Izzard said, after he crossed the line in Pretoria, sipping from a bottle of champagne. "I have a huge blister and I'm exhausted."

One man who can empathise is Rory Coleman, who ran 28 marathons in 28 days in 2013 and 43 ultra marathons (double marathons) in 43 days in 2004. Altogether the 54-year-old has done 971 marathons.

Izzard's exertions should do him no harm in the long term, Coleman argues. "He's running the marathons very slowly, running and walking them," he says. "He's not going quick enough to break his body. He is using his body for what it's designed for. We are not designed to sit at desks and answer email. We are designed to run across a plain all day. That's what we are - hunter-gatherers."

Image copyright Getty Images

Running marathons every day for a prolonged period means "you actually get fitter, and the distance becomes less of a challenge" because the lungs improve and the body gets lighter, he adds.

Izzard has risked severe damage to the knee ligaments and there's a strong likelihood of "massive muscle damage", says Peter Jones, head of Staffordshire University's school for psychology, sport and exercise. The immune system will be suppressed during the initial recovery, leading to a greater risk of infection.

Izzard's recovery should take about a month and involve plenty of low-impact, low-intensity training, such as swimming, plus stretching exercises. "What he's done is a little bit extreme, I guess," says Jones," but he should be back to normal after a few weeks, so long as he hasn't done any major damage to his body."

Most research on damage to the body caused by high-impact sports is based on single events, such as a rugby match or a marathon, whereas Izzard's feat is unusual because it involved a repetitive action - running or walking - over such a long period, says Jones.

Top marathon-runners today complete the course in not much more than two hours. Elite athletes take part in only two or three full races a year, aiming at peak performance, rather than constant repetition of effort."Ordinary" marathons were once considered towards the outer reaches of human capability. But today organised events, such as the Marathon des Sables, in which competitors complete the equivalent of five-and-a-half marathons through the Sahara Desert in six days, while carrying backpacks, push the human body to its limits.

When he was 42, Coleman ran 30 miles a day for 43 days for endurance event ending in the Portuguese capital Lisbon. He thinks the physical and psychological impact was so huge it took him four years to recover fully.

Physical exercise, while not actually a drug, "possesses many traits of a powerful pharmacological agent", according to an article published in 2012 by the US National Center for Biotechnology Information. And an "upper-dose limit potentially exists", after which there could be problems for the heart and bone structure, it added.

Image copyright Getty Images Image caption Running a single marathon was once considered an extreme of human endurance

Image copyright Getty Images Image caption But in recent decades marathons have become mass-participation events

But, says Jones, the basic advice to aid recovery after a marathon still applies after Izzard's feats. A few hours after a marathon's completed, delayed-onset muscle soreness can hit. For the first 24 hours after the race, runners should apply ice-packs to their legs for several minutes at a time and to elevate them for an hour at a time to help pump out impurities.

Energy levels will also be low, meaning high-carbohydrate meals are recommended, as well as plenty of protein to repair muscle and tissue damage. Foods rich in iron are good. Some runners put on weight after the marathon, which is usually because of water retention. This is a bad time to start a weight-loss regime and runners should keep eating a full range of nutrients, says Jones.

Many athletes report having "the blues" after completing a huge goal, such as a marathon or a triathlon.

"There is a low after any kind of big rush, whether professional or personal, and you wonder where you are going," says François-Xavier Li, a lecturer at Birmingham University's school of sport, exercise and rehabilitation sciences. "For a month or more he has thought only of that and suddenly there is a big void to fill. He does seem to be a guy with big projects anyway, so he is unlikely to remain idle for long."

It will be difficult to recreate such excitement, though. "It's that Neil Armstrong thing," says Coleman. "Once you've been to the moon everything else is really dull, isn't it?

"This type of feat is more of a pilgrimage. What happens is you park up all of your life, you leave it at the start, then you live in this strange land where all you are doing is running, then at the end of it, psychologically, you just run straight into a brick wall. And that's the hard bit. I bet today he actually wishes he was running."

But Izzard offers some advice that many more might want to follow: "This was tough. Don't do this at home."

More from the Magazine

How will 27 marathons affect Eddie Izzard? (February 2016)

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