Here’s an old translation of verses 11 and 12:
“But you, O man of God, flee these [bad] things, and run after justice, godliness, faith, charity, patience, mildness. Fight the good fight of faith: lay hold on eternal life, to which you are called…”
So basically, the idea is that we’re athletes in the Olympics of faith, and if we’re like runners, we have to run towards good things and away from evil things. If we’re like boxers or wrestlers, we have to fight as well as we can, so that we can win the prize of eternal life.
Basically, you want to try your best for God, whatever you’re doing.
It’s a good analogy, because a lot of people work harder on sports than on life!