In favour of getting fit for personal advantage (3)
I believe the answer is:
pro
This clue is a quadruple definition!!
'in favour of' is the first definition.
(being pro a particular cause)
'getting' acts as a link.
'fit' is the second definition.
The definition and answer can be both related to communication as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'for' is the third definition.
(as in being 'pro' or in favour of something)
'personal advantage' is the fourth definition.
'pro' can be an answer for 'advantage' (as in pros and cons). I am not certain of the 'personal' bit.
Can you help me to learn more?
(Other definitions for pro that I've seen before include "Favouring the professional" , "With qualifications" , "Professional; advantage" , "gets paid to play?" , "Golfer" .)