Rob Greenfield has done lots of stupid stunts. He’s walked 10km barefoot around New York and hitched 1,300 miles from Cabo to San Diego but his 2013 expedition was his grandest yet.

Over 103 days he cycled 4,300 miles across America, from San Francisco to Vermont. All without electricity, bottled or tap water or a support team.

His ‘Off the Grid Across America’ challenge was designed to raise awareness of the environment and during his journey he survived on water from leaking fire hydrants and puddles, food in dumpsters and insects – often in the nude.

His incredible feat was news all over the world and showed just how tough the human body can be in pursuit of the right cause.