Hitting Your Physical Limits

About two weeks ago, I was in my martial arts class paired up with a teenager roughly 1/4 my age.  We were practicing various self defense techniques against a variety of wrist grabs.  Being a 3rd degree Black Belt, I had no problems performing the techniques.  I’ve been doing them so long that they’re almost second nature.  But then it was his turn. “Go slow,” I said as he struggled to get his hands in the right position.  However, when the Instructor yelled, “Begin,” he didn’t go slow at all.  He increased the torque on my wrist from 0 to 110% faster than I could tap out and before I knew it, I was on the ground hollering and holding my newly-sprained wrist as the searing pain subsided. “What...