up to 6,000 runners are set to descend on the tracks and trails of the blue mountains for one of the world's most challenging ultramarathon events.read moreamong those taking part over the gruelling 100-kilometre ultra-trail australia course are 79-year-old bert sloane and 75-year-old alf johnson. `i like being in the bush. i like the freedom of running there and i like the people i run with,` mr sloane told sbs news.mr johnson said: `people know me because i'm the only one that starts the 100km in a flannelette shirt.`with a combined age of 154, mr sloane and mr johnson live out the motto of `never give up.``well, i plan to live forever. i'm going okay so far,` mr slone said.