Half marathon in hot air balloon

An Australian runner has taken the sport to a whole new level - by running a half marathon in a hot air balloon.

Rob Ginnivan, 47, completed the 13-mile run on a small treadmill in the basket of a hot air balloon above Canberra.

He had to battle freezing weather and high altitudes to complete the stunt, in aid of the Heart Foundation charity.

But the seasoned runner said the toughest part of the challenge was that he was able take only small steps as space was restricted.

"What I didn't count on was that the basket actually tilted, so it was like running up a hill," Mr Ginnivan said.

"Every time I took a step the basket would sway from left to right so I kind of had this sea type motion being in the air. It was quite bizarre and made it very difficult."