The Call of the Cup

[CrackS]

...NFL players are not just running against friction of grass, but getting hit in the opposite direction.  In hockey, most hits are at a significant angle, ...

A lot of hits in hockey are a complete change in direction.
Example: http://66.98.192.76/broadstreetbully.com/paulnailed.mpg

[Raven]

You seem to loose sight of the fact that NFL wide recievers are running full speed for what? 5-10 seconds? Then get a 35 second break. Then run for another 5 seconds. Then another 35 second break. Then run for 10 seconds. Then another 35 second break.

I think I'll have to disagree on that one. Going into a dead sprint for 10 seconds takes alot out of you, even if you get a 30 second break afterward. The player has to run at full speed (the receivers almost always need to sell that they're going for a pass, otherwise it's almost a dead giveaway that it's a run). Then, they have to jog back to the line of scrimmage, take a small break, and run again. This requires plenty of endurance, as receivers will be doing that for quite a while; sometimes an especially long stretch if the offense stays on the field for a while. And don't forget the receivers aren't the only position in football. RBs sometimes have to serve as workhorses, rumbling through the lines, running as fast as they can while dodging 300lb linemen. And don't forget the linemen themselves that have to run, hustle, push, block, runblock, etc. time after time. While hockey demands tons of endurance itself, it's not like they're skating full speed all the time. You'll only really see hockey players skating full speed when they're going for a puck or a guy who's controlling it. They spend plenty of time sorta skating zone in certain places, so it's not like they have to be exerting all the time. Plus, there are plenty of line changes to keep players as fresh as possible. Ofcourse, both sports require enormous levels of endurance, but it'd be really difficult to determine which sport requires more. IMHO, like Grok said, NBA players probably need the most "stamina", as far as hustling up and down the court goes, but then again, they usually don't have to deal with nearly as many collisions and physical contact as players in the NFL and NHL. Either way, I just don't think you can compare different sports as far as which is the most demanding; there are many different variables to weigh and consider.