Football players have an expansive 100-yard field, and spend hours moving up and down it. So it would seem like they do a lot of running. That's true enough—while the ball is in play. But according to the Wall Street Journal,
players are only actually moving for 11 minutes on average during an NFL game 
. Only 11 minutes of action! The rest is mostly standing around, with the occasional momentum-killing penalty review thrown in for good measure.
Kinda breaks the heart, doesn't it? Again, turning to a chart over at SportVU,
it seems that even the players that run the most (cornerbacks and wide receivers, generally) only run about 1.25 miles per game. That said, some of them are reaching speeds of 21.5 miles per hour, which is scary fast for dudes that size.