The big legs would be those of the forwards, and the reason boils down to one thing. Scrums. Diet is whatever their nutritionist dictates -- and any serious player is going to be consulting a nutritionist to help with the diet. The only thing which is true of every player's diet is that they are all going to be protein heavy with (probably) a milk protein based supplement. Egg whites work well too. Exercises are what you would expect to develop power in the thighs and core. Power cleans, squats (front or back) and deadlifts. They would also train by pushing heavy sleds or a scrumming machine.
run up hills bro, squats with dunbbell's then straight into lunges rep's are lame just go till you cant do anymore hha
Diet, run, squats!
