Ranulph Fiennes ended his self-imposed challenge with a race in New York which he finished in just over five hours 20 minutes on Sunday.
Fiennes and running partner Dr Michael Stroud joined 30,000 others in the 42km run after running a similar distance in Cairo on Saturday.
“It’s the best thing possible,” Sir Ranulph said at the finishing line. “It was good fun. We thought it would be and it was.”
The feat was all the more remarkable given the punishing jet lag Fiennes must have suffered after arriving in a city almost a full working day behind the Middle Eastern time zone.
The adventurer admitted running nearly 300km in a week had been “very knackering on our legs”.
In Cairo on Saturday, he raced through the night, after just four hours’ sleep. Despite the heat and Ramadan traffic he managed to better his Friday time in London of four hours 41 minutes.
The pair had completed runs on the Falkland Islands, Santiago in Chile, Sydney, and Singapore earlier in the week.
The Singapore race, run in tropical heat and humidity, was the biggest challenge.
Fiennes described the experience as “hell on Earth” – especially for a man who has suffered a heart attack and undergone a double heart bypass operation.
He had also been running with a defibrillator to safeguard his health.
All money raised from the Land Rover 7x7x7 Challenge will be given to the British Heart Foundation. They hope to raise a six-figure sum.