Athlete or climber (bean-pole type) (6)
I believe the answer is:
runner
'athlete' is the definition.
(runner is a kind of athlete)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for runner that I've seen before include "Athlete - errand boy - strip of cloth" , "Type of bean for an athlete?" , "Kind of bean for an athlete" , "Canvas shoe with a rubber sole" , "Percussion instrument" .)