id suggest the frying pan test next
have someone whack it on your head
and post the results
Dude, seriously, who told you to do that? I don't think I need to explain why that is a dumb@ss idea. And no, hitting yourself will not help.
Cardio for stamina. You don't need to hurt yourself to adapt to it. Endurance workouts are probably more suited for you.
I can hit myself on the legs or head, or stomach, and not feel pain, same applies to others hitting me (not violence, I'm fine).
How does this work, do my muscles adapt to it, and how do I increase this ability more efficiently?