I've often thought about something along these lines - not to run a whole marathon as was originally suggested, more like: "I'm going to run 4 miles after work

I've often thought about something along these lines - not to run a whole marathon as was originally suggested, more like: "I'm going to run 4 miles after work tonight at an 8:00 min/mi pace, anyone want to join me?" I definitely think this idea's got legs...