One-time marijuana use - how quickly would a distance runner work it out of his/her system?

Well THC is fat soluble and not water soluble so you're not going to sweat it out. The rule of thumb is that it stays in your system for up to 30 days. But one time ? Don't worry about it.

[quote]Deadman Running wrote:

The rule of thumb is that it stays in your system for up to 30 days. quote]

Actually, detection is 3-4 days at most for someone who used it once. A chronic pothead might test positive for 10 days to two weeks.

It does stay in hair for up to 90 days, if that method is used for testing.

Yep - I agree. I know a few people that due to "circumstances" have had to undergo monthly testing, and they said they could have one to two hits per week and pass the drug test. Above that they would test positive. But to the OPs question - one time ? Fugettaboutit - non-issue.