Stress a Good Thing?

A sentence in a motivational book reads: Stress ..."can be a good thing-- a little stress can heighten your senses and productivity."  That is very enlightening however, how do we keep it within the so called "good" limits?    Is it possible to simply check yourself back and think: "WHOA - Joanne!. You're exceeding the healthy stress level so just relax a minute."  Who is that talking anyway? What does SHE know?  This is what SHE thinks SHE knows.  Start by taking a deep breath and begin talking to yourself using all positive statements (don't worry about those people staring).  Express emotions and [...]