Video report by ITV News Correspondent Sejal Karia
A British endurance runner known as Adventureman has completed an epic 210 marathon, 5,500 mile coast-to-coast tour of America, raising thousands for charity in the process.
Jamie McDonald, 32, who has a rare spinal condition as well as epilepsy, ran from America's westernmost point, Cape Alava in Washington, to Gloucester, the city in Massachusetts that shares its name with Jamie's UK home town.
He was joined by hundreds of Gloucester, Massachusetts residents, many also wearing superhero costumes, as he crossed the finish line.
Having spent the first nine years of his life in and out of hospital with a condition known as syringomyelia, Jamie used the run as a platform to gain charity donations for sick children, raising $200,000 during his run across the US.
During his epic challenge, he visited twelve children's hospitals, hoping to inspire children as he ran through 21 of America's 50 states, wearing the costume of his superhero alter-ego Adventureman for every one of the 11,608,344 steps.
"My body is in pieces. I can feel the aches of every single one of those steps," Jamie said after touching the east coast sea.
"I wouldn’t change it for the world, and could not be more thankful for the support I’ve had and continue to receive."
In the course of the run Jamie encountered some unusual scenes and while straddling America's southern border with Mexico, he was even stopped by police who suspected he was a runner for a drug cartel.
Fortunately most of his experience was captured on camera and many of the hilarious moments were shared on social media.
Being confused for a ‘Mexico border drug runner’
Monsoon and lightning strike
Close encounters with a mountain lion, scorpions and spiders
He said: "I’ve run through freezing rain forest downpours and the Arizona desert summer.
"I’ve been caught up in a freak flood that devastated a town, camped in places surrounded by bears, cougars, mountain lions, spiders and snakes.
"If I didn’t have video proof even I’m not sure I’d believe me!"
The prolific fundraiser, who won a Pride of Britain award in 2014 for his charity work, says his mission is "to ensure no child goes without treatment they need but can’t access or afford".
Looking ahead to another fundraiser he said: "I’m going to have a well-deserved couple of weeks away from running, until I lace up my trainers again to attempt the treadmill seven-day distance running world record at the end of April, back home in Gloucester."
He's hoping to hold the record for 'the greatest distance covered on a treadmill within one week', which currently stands at 513.97 miles.
If he achieves his goal, it will be his second world record - he also holds the Guinness World Record for marathon static cycling, having pedalled for 268 hours.
Jamie is co-founder of the charity Superhero Foundation, which grants money to families for treatment, and has provided more than £300,000.