Wall to wall: Australians crash into each other at full speed
The unusual competition is called Runnation: participants race toward each other across a small arena equipped with mattresses. Doctors call the sport dangerous, while fans call it a new way to get their adrenaline pumping.
Runnation gained popularity after a tour in Sydney, videos of which attracted the attention of online users. Several "fights" are already planned for Las Vegas and Seattle.
