Astronaut Tim Peake on running London Marathon in space

Tim Peake is one of thousands taking part in the London Marathon on Sunday - but he's the only one doing it in space.

While earthbound athletes aim to complete the standard 26.2 miles or 42 km, the astronaut is likely to cover some 100,000 km - thanks to travelling at 27,600 km/h on the International Space Station.

"It's like running with a clumsy rucksack on" says Major Tim of the harness that chains him to the treadmill.