On the last day, because of earlier disruption, he did a double marathon to ensure he reached his target.

One man who can empathise is Rory Coleman, who ran 28 marathons in 28 days in 2013 and 43 ultra marathons in 43 days in 2004.

“He’s running the marathons very slowly, running and walking them,” he says.

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.

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, was Izzard’s feat is unusual because it involved a repetitive action – running or walking – over such a long period, says Jones.

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.

Says Jones, the basic advice to aid recovery after a marathon still applies after Izzard’s feats.

Some runners put on weight after the marathon, which is usually because of water retention.

Eddie Izzard