The fourth annual “Naked Pig Run” took place in Beijing’s Olympic Park last Sunday, and although the city’s smog levels were even higher than usual (that's saying a lot), over 300 runners braved the toxic air.
The rule of the run is simple – you run in your underwear, nothing else.
But when the air is just that bad, event organizers allowed runners to bend the rules a little regarding running attire:
[Photos from China Daily
and Getty Images]