Clothes for athletes (7)
I believe the answer is:
jumpers
This clue is a double definition.
'clothes' is the first definition.
(jumpers is a kind of clothes)
'for athletes' is the second definition.
(jumper is a kind of athlete)
(Other definitions for jumpers that I've seen before include "suitable for spring?" , "Garments" , "They warm you up" , "get you going when powerless (in > play)" .)