Where to even begin This has to be a troll job
Ya my back is probably one of the bigger muscles groups on my body, along with the forearms and lastly my cawk
I'm pretty sure I remember reading or watching he does a lot of sparring where they throw in a new fresh opponent for him in between rounds to mix...
Depends on the person and a bunch of other things like Diet Lifestyle etc.....
Hit it properly or with an instructor, but other then that every day.
Running is good for you plain and simple, try mixing sprints into a long distance run to work your cardio for different spurts of intensity as well.
Left hook takes a lot of practice, and by practice I mean a ton of practice. Spar more, hit the bags more, do some mitts. Just throw lots of left...
