Nick is asserting that attack through words is weak and cowardly; one can say much but it is often one's actions which are judged. He feels it is more noble to act on one's emotions with physicality rather than react with taunts and empty threats. He is of course trying to save face by fighting valiantly with a foe who is indeed a match for him, but is a woman.
The context of the statement is that in Chapter 21 it is revealed that the fight Nick had with Julian ended with him discovering that 'Julian' is a girl. Nick had taken himself to the ale-house to console his wounded pride. He is fired up when Sander reveals publicly 'Julian's' gender and he is then ridiculed. Nick finds it easier to deal with physical defeat than he does the mental defeat of being outwitted by a mere woman.