Concerning that woman, one in sales with no energy for preliminary trials (10)
I believe the answer is:
rehearsals
'sales with no energy for preliminary trials' is the definition.
I can't judge whether this definition defines the answer.
'concerning that woman one in' is the wordplay.
'concerning that' becomes 'rehears' (I can't justify this - if you can you should give a lot more credence to this answer).
'woman' becomes 'Sal' (short for Sally).
'one in' indicates putting letters inside.
'rehears' placed around 'sal' is 'REHEARSALS'.
Can you help me to learn more?
(Another definition for rehearsals that I've seen is " Practice sessions".)