Answer: exerting

AnswerCrossword Clue
EXERTINGGoing all out
EXERTINGPutting into action.
EXERTINGUsing energy
EXERTINGPutting out
exertingto put forth
exertingto put in force
exertingto put (oneself) into vigorous effort
exertingEXERT, to make an effort