Carbert rises early each week to do some stretches first at home, and runs in all weathers unless there is deep snow or ice.
He said he was full of trepidation when he went along for the first time, aged 77.
“I didn’t want to make a fool of myself, but everyone welcomed me.
“You know it’s one big happy family here.”
Carbert said he achieved his personal best running time of 28 minutes and 13 seconds aged 80, but now completes the 5km (3.1-mile) course in around 38 minutes.
“I think it will have added years to my life.
“Really, I didn’t want to sit around at home vegetating.”