Is anyone else doing this? Has anyone done it before? I heard about it from my WW board and decided to join up. So far I only have 4.2 miles, but I think it'll be good motivation and it'll be interesting to see how far I go while I train for my next half marathon. It's pretty cool and you can do it with biking/walking/or running. I'm doing walking and running because I figure it will take me forever to get through it all.
http://exercise.lbl.gov/index.html