Interesting poll in that the top choice is actually one that might get one closer to running a sub-3:00 marathon. If these folks were to run, instead of watching TV (what's the average TV diet of an American?) they could get much closer to a sub-3:00 time.
Training and diet, other factors apply, but seriously, lets say the avg American watches 1.5 hrs of TV per day (way low if you ask me). That is potentially a lot of volume.