O-dark thirty is a term that's used alot around the Army. It usually refers to anytime before sunrise, when we have something going on like a mission, or training, and someone thought it would be a good idea for us to show up just in time to wait around for 2-3 hours before we get started. I like running at dawn, and again at sunset. Those are my favorite times of the day, it's so beautiful out.

I think O'dark thirty is military talk for 5:30am, not sure. Anyway, running first thing in the morning doesn't interfere with work or family time. But granted we don't see a lot of others runners out at this time of day. Seems the fastest runners are out at 8 or 9am. It helps having others to meet up with because otherwise there is no way I am getting out of bed at 5am.

So when exactly is "o-dark thirty"? Is it mandatory that marathon runners run at the crack of dawn or is it just a popular trend?