Interesting article from the guy who reworked Brian Urlacher's training program back in 2004.

The Design Challenge
Urlacher wanted me to design a program to help improve his fourth quarter endurance. I've always trained Urlacher position-specific by having him work on scraping and filling, pursuit drills, first step explosion, pass drops, change of direction and any other drills to benefit his position at Mike Linebacker.

The first challenge in designing the kind of program Urlacher wanted was figuring out why he was tiring so much in the third and fourth quarters. To start, I had Urlacher send me game cuts from four games. I broke each film into different segments by charting each play, starting with the first series. That included the quarter, down and distance, Urlacher's position on the field and the actual play (blitzed the A gap from the right side, for example). Then I broke down each game into four quarters. Each quarter represented actual game movements from the four games Urlacher played. I included 25 seconds between each play, T.V. timeouts and halftime.