Video Game: Mario Kart 64 (1997)
If racecar drivers can be seen as athletes in real life, then Mario Kart drivers can certainly be considered fictional athletes. While there are arguments to be made for all the characters, especially the perennially in danger Princess Peach, there is a fairly clear winner.
For all his life, Bowser has been trying to best Mario through not-so-complicated kidnapping schemes. If only he had known that he just needed to rev up a cart and start racing because that's just about the only way he'll ever defeat Mario. Coming in as the fastest of the heavy-weight racers, and pretty big in his own right, Bowser can use his solid acceleration skills to smash into other racers and cross that finish line without seeing tailights with regularity.