Possible Clues:

• Race the old lady runs with unusual hat on
• Doctor at no harm in the long run
• Battle remembered in the long run?
• Mum competed, taking on terribly hot gruelling event
• Run a sheep over, though near losing attention
• Race that's 26.2 miles long
• It’s something to run a temperature: no harm moving around outside
• Smart maths done ignoring all tips for race
• Running portion of an Ironman race
• Scene of a Greek victory over the Persians in 490 BC