Put new energy into troubled lives -- one gets little thanks getting involved (8)
I believe the answer is:
Here is my best explanation:
'put new energy into' is the definition.
'troubled lives one gets little thanks getting involved' is the wordplay.
'troubled' indicates an anagram.
'one' becomes 'i' (Roman numeral).
'gets' is a charade indicator (letters next to each other).
'little thanks' becomes 'ta' (short way of saying 'thank you').
'getting involved' indicates putting letters inside.
'livesi' anagrammed gives 'vilise'.
'vilise' going around 'ta' is 'VITALISE'.
(Another definition for vitalise that I've seen is "Stimulate activity".)