Manage the marathon maybe (3)
I believe the answer is:
run
I believe this clue is a double definition.
'manage' is the first definition.
(both can mean to organise)
'marathon maybe' is the second definition.
(I know that marathon is a type of run)
'the' acts as a link.
(Other definitions for run that I've seen before include "Go swiftly - ladder" , "journey" , "Jog; manage" , "A single" , "Move fast with the hens?" .)