Loop-the-loop - the people who run around in circles for 24 hours

In the heart of London at midnight, rain is splashing against the pavement. While the majority of the city rests, a solitary figure on an athletics track south of the River Thames is tirelessly running laps, drenched and shivering in shorts, a T-shirt, and a makeshift gilet made from a black trash bag.

Nearby, a pensioner who arrived from Norway earlier that day is also jogging, clad in a blue poncho from a discount store.