Cut out physical exertion, without hesitation (6)
I believe the answer is:
excise
'cut out' is the definition.
(thesaurus)
'physical exertion without hesitation' is the wordplay.
I cannot really understand how this works, but
'without' could be 'ex' (I've seen this in other clues) and 'ex' is present in the answer.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for excise that I've seen before include "Type of tax" , "Internal tax" , "Customs" , "Cut out; commodity tax" , "A tax to be cut out, perhaps" .)