So you think you know what it means to be an elite athlete? When did you last see an olympian marathon runner dose themselves with rat poison to enhance their vigor?
When nothing forbidden, everything is permitted.
Take your runner through unique courses. Each play session (ca. 1h) will see the players (3-5 of them) doing whatever they can to get their own runner to the finish. Wether it be giving your rider a lift with an automobile or chasing an opponents runner away from the track with a pack of rabid dogs.