"To give anything less than your best is to sacrifice the gift." -- Steve Prefontaine
When you enter earth god blesses you with a gift of some sort. Everyone is blessed with some kind of gift; the challenge is finding what it is. Many people may search their whole life searching for what their special gift is. What they might find in the end is that you may not have to be exceptionally good at something to have the gift.
If you enjoy doing a sport, even if you are not the best at it you should do it anyways, and try your best. When you can distinguish those with strong will compared to those without, is by whether or not they accept the gift as a challenge to grow and get better, or if they just throw it away. There are only so many things in your life that you may consider to be one of your gifts. To throw any one of them away is like throwing away part of your life.
I feel I have been very lucky at being gifted in many different sports. I do football, basketball, and track, which I love every single one of them. I feel if I do not do every sport at the best of my ability; it is like abusing the gift. If you love doing something then you should always do them to the best of your ability. There is always someone watching you admiring the effort you put forth, even when you don't expect it. Whether or not you are practicing a sport, writing a book, or painting a picture, always do it to the best of your ability, if you don't you will always regret what you sacrificed. This is why "to give anything less than your best is to sacrifice the gift."