I participated in this years Great Place to Run event for Intel. I ran the 5k and leaned (or more likely relearned some important lessons):
1) You should really train for these things. I haven't run for many years and it showed. I had to walk some portions of it and I am SO sore.
2) Walking is good when you aren't prepared. I could have got a better time, but at what cost? I didn't want to injure myself.
3) I like running. It feels good.
4) Sunscreen is important, even on a cloudy day.
Place: 506/1443 Overall, 362/784 among males, 64/99 among males 30-34