A man dressed as the Monkey King, a main character in the Chinese classical novel Journey to the West, participates in the annual Undie Run on March 1 in Beijing. Now in its fourth year, hundreds of runners clad in various costumes took part in the 3.5-kilometer-long race at the Olympic Forest Park. Organizers said they aimed to advocate healthy living. Photo: Cui Meng/GT

A runner sporting Superman undies and “environmental protection” written on his chest takes part in the Undie Run on March 1 in Beijing. Photo: Cui Meng/GT

A female runner poses as a fitness instructor during the Undie Run on March 1 in Beijing. The label on the runner’s waist reads “nühanzi”, or “tough girl”. Photo: Cui Meng/GT

A man pushes a baby in a stroller during the Undie Run on March 1 in Beijing. Photo: Cui Meng/GT

Runners clad in leaf skirts take part in the Undie Run on March 1 in Beijing. Photo: Cui Meng/GT

Photo: Cui Meng/GT

Photo: Cui Meng/GT