Wishing Well

Last Friday I was saying goodnight to my friend Brian, who was about to run a marathon in a couple of days. As he was walking off, I realized that I wanted to say something encouraging about the race, but didn't have a good phrase on hand.

• "Good luck" – Hopefully the race won't involve any luck.
• "Have a good race" – Not bad. Sounds like what you say when someone's going on a picnic, but not bad.
• "Break a leg" – Um, no.

I'm really not sure what to say to someone, or what I want to hear, before a long race. I feel like we runners could use something short and pithy like "break a leg," but I can't think of anything.

• "Show 'em how it's done!"
• "Go long!"
• "What are you, nuts?"

These all have their points, but... not quite.

Any suggestions are welcome.