They will bother runners? (8)
I believe the answer is:
harriers
I believe this clue is a double definition.
'they will bother' is the first definition.
(harry can mean persistently attack)
'runners?' is the second definition.
(common team name for cross country runners)
(Other definitions for harriers that I've seen before include "Fences" , "Groups of cross-country runners" , "Group of cross-country runners" , "Birds" , "Hunting dogs" .)