1 Corinthians 9:26
Therefore I do not run aimlessly; I do not fight like I am beating the air.
What it says
So Paul says he does not run aimlessly or box as one beating the air.
What it is doing
It applies the athletic image directly to his own life.
In context
24Do you not know that in a race all the runners run, but only one receives the prize? Run in such a way as to take the prize. 25Everyone who competes in the games trains with strict discipline. They do it for a crown that is perishable, but we do it for a crown that is imperishable. 26Therefore I do not run aimlessly; I do not fight like I am beating the air. 27No, I discipline my body and make it my slave, so that after I have preached to others, I myself will not be disqualified.