A racer is fit because he needs it to be able to compete at high level competition. Not that, he would flaunt his body over the other racers, but being fit means that you are able to last a long time. And a race do last a long time and unfit racers could be seen easily since they won't last long.
Wait for the signal to be given before starting your engine. Drive your car as fast as you can till you finish the race. Maneuver your car over and over again since that is what you need to do in order for you to win the race. And don't forget to upgrade your car if you have the money.