This is Jamie McDonald from Gloucester. He's running across Canada to raise funds for a number of children's charities.
The incident happened yesterday after he arrived in the ski resort of Banff, Alberta.
He was beaten about the head and his bag containing his hard drive, wallet and camera was stolen.
As a child, Jamie suffered from a rare spinal condition known as syringomyelia, as well as a very weak immune system.
He began his attempt to cross Canada coast-to-coast in March 2013.
He's running in aid of Great Ormond Street Children’s Charity, SickKids Foundation and the Pied Piper Appeal, along with children’s hospitals throughout Canada.
The coast-to-coast run is the equivalent of more than 200 marathons in 275 days.
He'll become the first person in history to run it alone if he completes it. The challenges he faces include snow storms, -30°C temperatures, and grizzly bears, all while carrying a 30kg backpack.
You can donate to his appeal here.