The more, the better.
My one armed master has been teaching me to use chi for years. I have yet to turn my hair gold though. Must keep trying.
Sparkling herbal mineral water.
... no seriously.
None of the options are right. My chi level is either 1006 or over 9000, depending on whether you are wearing your scouter upside-down. :P
To me it's a poorly defined word that 99.9% of the time is used to refer to some magical power (aka bullshit) as opposed to being applied to something real like adrenalin or better health (which leads to better endurance/conditioning, etc.). Or the extra power that comes from learning better technique. Etc etc etc.
It's used incorrectly enough times to justify saying bullshit but I just wanted to add that there is a small minority that applies the word to something real.
It's the energy Ryu uses to blast you with his Hadoken. Only those that trained under Sheng Long can hone it!....
What I really think is they're different terms to describe an old concept that exists in many cultures, however nowadays I think it can scientifically be described as the placebo effect of your state of mind, drive, determination, so nothing fancy about it really.
What is chi, and how is it harnessed?
"A living thing seeks above all else to discharge its strength - life itself is Will to Power. Nothing else matters."
How well you express your will in combat is a function of your training. Simple as. Everything else is bullshit.
...and on my first post, no less.