In calling the church in Corinth to spiritual disciplines that will keep them living lives empowered by the gospel, Paul uses the examples of athletes training for the Isthmian Games so popular in Corinth.
1 Cor 9:24-27
24 Do you not know that in a race all the runners run, but only one gets the prize? Run in such a way as to get the prize. 25 Everyone who competes in the games goes into strict training. They do it to get a crown that will not last; but we do it to get a crown that will last forever. 26 Therefore I do not run like a man running aimlessly; I do not fight like a man beating the air. 27 No, I beat my body and make it my slave so that after I have preached to others, I myself will not be disqualified for the prize.
Therefore, since we are surrounded by such a great cloud of witnesses, let us throw off everything that hinders and the sin that so easily entangles, and let us run with perseverance the race marked out for us. 2 Let us fix our eyes on Jesus, the author and perfecter of our faith, who for the joy set before him endured the cross, scorning its shame, and sat down at the right hand of the throne of God. 3 Consider him who endured such opposition from sinful men, so that you will not grow weary and lose heart.
Not that I have already obtained all this, or have already been made perfect, but I press on to take hold of that for which Christ Jesus took hold of me. 13 Brothers, I do not consider myself yet to have taken hold of it. But one thing I do: Forgetting what is behind and straining toward what is ahead, 14 I press on toward the goal to win the prize for which God has called me heavenward in Christ Jesus.
2 Tim 4:7 – 8
7 I have fought the good fight, I have finished the race, I have kept the faith. 8 Now there is in store for me the crown of righteousness, which the Lord, the righteous Judge, will award to me on that day—and not only to me, but also to all who have longed for his appearing.