1. Training: http://jasoncholewa.com/2013/07/27/w...ey-cannot-lie/ Bam!
2. Were you heavier when you played football? I notice that most people who lean out lose a lot of overall volume in their glutes, and most people who are lean to begin with do not have voluminous butts...unless they are really genetically gifted. When I gain weight my butt gets huge, when I lose weight it shrinks. Right now you can see some striations in my glutes...however, it is not Larry Fitzgerald like. Based upon your aviator pic (how lean you are) I don't think you will need to worry about not fitting in your jeans unless you put on upwards of 3-5% body fat.