Can anyone explain what exactly is meant by "expand the rib box"? Does this refer to enlarging muscles that are on the exterior of the rib cage, or does it actually mean expanding the rib cage (i.e, bones) itself by, for example, developing muscles inside of it. If it means the latter, then I would think older guys would not be so interested, as we become barrel chested with age naturally (much like smokers do). For example, if you look at a 35 y/o pro cyclist compared to how he looked as a 25 y/o, you see that they typically have much bigger chests, and it isn't from pec development for damn sure. However, if it refers to keeping the ribcage itself the same size but increasing musculature outside of it, then that's sounds like something I might be interested in.