Adrenalin

I was curious to know if anyone had any tips on training one self to be able to release adrenalin at will. I remember reading somewhere around here that it was possible. If you have any information on this I would be greatful. I tried doing a search but nothing came up.

usually when i need to i just think of something that once scared me or someone who has hurt me(or someone i care about)

then again that barely ever works