A 12 hour run is a form of ultra marathon in which a competitor runs as far as they can in 12 hours.
A competitor runs as far as they can in 12 hours. A 12 hour run is another form of ultra marathon.
A 12 hour run is another form of ultra marathon. A competitor runs as far as they can in 12 hours.
A 12 hour run is another form of ultra marathon. A competitor runs as far as they can in 12 hours.