A British adventurer will today finish his 5,500 mile, 210 marathon coast-to-coast run across the US – by dipping his hand in the Atlantic Ocean.

Jamie McDonald, 32, is ending his mammoth run in Gloucester, Massachusetts – 11 months after starting his trip dressed as superhero Adventureman.

During the run, Mr McDonald has visited sick children in hospital and has raised more than 150,000 US dollars (£114,000) along the way.

The former tennis coach, from Gloucester, started his feat in April last year by dipping his hand in the Pacific Ocean at Cape Alava in Washington, the most western point of the US, and has taken more than 11 million steps.

He has so far completed 205 marathons, recently even running 75 miles – just shy of three marathons – in one day alone.

On Wednesday, Mr McDonald will run his final six miles to the beach at Fort Point in Gloucester and is calling on people to join him, especially if they are wearing superhero costumes.

Running by himself and without a support crew, Mr McDonald has battled through desolate and lonely deserts, sub-zero temperatures and the constant threat of wild animals, injuries and the uncertain elements.

When he returns to his home city of Gloucester in the UK, he will attempt to break the Guinness World Record for the greatest distance covered on a treadmill in a week.

The Briton said: “All I can ask is, please do keep donating. My fundraising goal was one million US dollars, and although we’re some way off that right now, I’m still holding out hope we can get closer to it, especially with the world record coming up.

“Please keep sharing, and please keep believing that we can make the world a better place for sick kids everywhere.”

Jamie McDonald has nearly completed his run across the US (Jamie McDonald/PA).
Jamie McDonald has nearly completed his run across the US (Jamie McDonald/PA)

Mr McDonald, who suffered from a debilitating immune deficiency and the potentially fatal spinal condition syringomyelia as a child, spent the first nine years of his life in and out of children’s hospitals.

He came to prominence in 2012 when he cycled 14,000 miles from Bangkok to Gloucester on a £50 second-hand bike.

Just weeks after returning to Gloucester, he set a new world record for cycling nonstop on a static bike.

In February 2013, two months after setting the new world record, he began his run across Canada.