How do footballers and boxers?

Question

have good stamina and be bulk

...

they be big and muscly with real good stamina how they do that

Answer 1

dude, its all about workouts and jogging

Answer 2

In their workout they balanced their weight training and cardio so they can have the added bulk from lifting weights and stamina from the cardio such as jumproping, running and calisthetics.

Answer 3

they constantly train and eat right.