Nothing in particular, like the guy said Marines go balls to the walls at everything, all the time. I've got one of the best and worst neighborhoods for training. I have a severely damaged right leg, & so far 1/2 cent is all my knee can take "in my neighborhood" I know I could do a century on most urban & suburban terrain. But I really like my hood, there is no traffic, no stoplights 2-3 stop signs and the altitude gain per lap is incredible, 50 miles I've climbed over 6,000 feet. I want to do a century in my neighborhood, to me that is a major accomplishment by most standards, until I can do that I wont be participating on any group ride having to listen to some 145lb guy telling me "ON YOUR LEFT". It's a Marine thing, I weigh 200lbs solid weight and i want to at least stay with the lead group, not necessarily at the front, that will never happen but maybe the middle. This is a typical ride around my block or at least this is the route I am using now. http://connect.garmin.com/activity/123297628