The good news is that Jesus loved us so much that he died for us.
NIV John 3:16 "For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life. 17 For God did not send his Son into the world to condemn the world, but to save the world through him."
Just as sin affected everything negatively, so the death of Christ affects everything positively. If we believe that Jesus Christ died to restore our broken relationship with God, then that has implications for the whole of our lives. And that must include how we participate in sports.
Remember too that the world of sports is part of God's creation. Just as God told Adam to work in the Garden of Eden and take care of it. (Genesis 2:15), we are to serve God is by using our talents in working at shaping his world for him. If our athletic talents are a gift from God, then it follows that we are to use them to work for God's pleasure as we take care of that part of our world.