Duċk;2534429
He's 5'11'', 255 pounds, and probably faster than most people here.
Except he (Jerome Bettis) is retired, and I'm not. I'm
obviously a harder worker.
To answer
Famine's question, the amount of running an American Football player performs at any one time is actually quite short, a quarterback has to make a lot of the decisions on where to run, where and how to throw the ball, dodge one or more 280-pound people looking to squash him...so he scrambles around a lot of he doesn't immediately hand the ball off to a running back. So a quarterback only has to run around 5-10 yards on each play.
A running back, fullback, or tight end is expected to get slammed my multiple linebackers (they play for the defense) for an average of 3-4 yards per play. A few times a game, he'll probably make 10 yards or more in a play.
The wide receiver (offense) or cornerback (defense) does the most amount of running per game, constantly running out 10-20 yards (or more) per play. On every play, the wide receiver has to run as quick as a 100-meter sprinter to catch the ball a quarterback thrown to him (or at least, near him....hopefully). The conerback has it even tougher, because he has to stay in close proximity with the wide receiver, without holding him back or tackling (it's not permitted until the receiver is within half a yard of the ball or has touched it), and yet he doesn't have a clue exactly what sort of play the quarterback and receiver have decided on, so he's got a guessing game to play.
The rest of the guys on offense are lineman or a center, and they don't so much move around as wrestle and tackle the other players as needed. On the defense side, there's the strong safety, who's quick enough to move in on whoever's been handed the ball, so he moves around about 5-10 yards on each play.
Special teams have a lot of running to do, but there's far less plays involved for them in a game. The players are expected to try to play both sides of the ball during kickoffs and punts. One minute, they're blocking, the next, they're trying to run down field and make a tackle. The kick returner is like a combo of the running back and wide receiver noted above, he's expected to run like heck in a minefield of tackles and blocks, for what averages 5-15 yards each on each catch.
The most a player can run in one time is 100 years, unless he's zig-zagging around in some weird end-of-game-desperation play. A good running back gets 4 yards per carry, and 100 yards a game is considered a success. A good wide receiver is supposed to get 100 yards "catching", but he likely runs around 3-4 times that in a game, manly to "trick" the other team.
Anyhow, make what you will of that. American footballers do not run around in the same sort of athletic fashion as a soccer player does, since he's expected to run around much of the time, especially if it's a midfielder. Play doesn't stop your matches unless there's a fire
and a riot. American football stops every 4-10 seconds, with an average 25-second gap between plays. There's also timeouts and referees that stop play on penalties, reviewing calls and even time-outs for TV ads.