Physically fit or strong (8)
I believe the answer is:
athletic
This clue is a double definition.
'physically fit' is the first definition.
(I've seen this before)
'strong' is the second definition.
(I've seen this before)
(Other definitions for athletic that I've seen before include "Sporting, vigorous" , "Vigorously active" , "Wigan, for example" , "Strong and active, good at sports" , "Given to partaking in sporting events" .)