Maybe not the long snapper but the vast majority of any NFL roster are physical specimens who have been in training their entire lives.
Yes, but they do strength training. Hiking a month in the backcountry takes endurance training more then strength.
I work as a backpacking guide in the Wind Rivers for 11 wks every summer. I have seen guys who are completely ripped, I'm talking massive muscles. Who give out after hiking 2 miles gaining 1000 ft. with a 45lb. pack. One guy was a fitness trainer at a SLC area gym, he was hugely buff. I figured he could hike circles around me. And guess what? flabby old me hiked circles around him, he was one of the slowest, whiny-est, wimpy-est man I ever guided.
Big muscle does not equal endurance.