Suitable physical training after first of August (3)
I believe the answer is:
apt
'suitable' is the definition.
(thesaurus)
'physical training after first of august' is the wordplay.
'physical training' becomes 'pt' (**).
'after' says to put letters next to each other.
'first of' says to take the initial letters.
The first letter of 'august' is 'a'.
'pt' put after 'a' is 'APT'.
(Other definitions for apt that I've seen before include "Liable" , "Prone" , "Tending" , "Ready to learn" , "Tap (anag.)" .)