:thinkwhat's the science behind this? i was under the impression energy comes from glycogen stores first, then some fat then some muscle.
It helps legs strenght and footwork. Every sportman that needs intense footwork has swole calves, like soccer players for example. Paquiao generates power through his whole body, that's the reason he works so much on legs and core workouts and not so much on upper body workouts. And his footwork and agility is amazing, he can cover the distance between he and his enemy before the opponent even have the time to lift his guard. Sometime is like he had a virtual reach of 6 foots or more, when he sprints forward with those leading left hands. Part of this is due to his legs. He doesn't just have swole calves, but also big quads. It could also have a part in helping the equilibrium, when a lot of your weight is in your bottom half its easier to move around in a stable manner.
Big calves - lower centre of gravity , helps hip speed to deliver punches that scare the **** out of four generations of Mayweathers.