Wellbeing, fitness (6)
I believe the answer is:
health
This clue is a double definition.
'wellbeing' is the first definition.
(I've seen this before)
'fitness' is the second definition.
(I've seen this in another clue)
(Other definitions for health that I've seen before include "It's said to be more than wealth" , "Physical welfare" , "Fettle -- condition" , "Fit condition" , "State of well-being" .)