I just read a very interesting paragraph from The Mental Keys to Hitting written by H.A. Dorfman. He talks about how to control your mind to control your muscles
The idea is that the athlete’s perspective will dictate the body’s behavior. Every time you’re unhappy with any aspect of your performance, first and foremost examine your perspective. Examine whether you are performing out of your emotional system or your rational system. Are you acting out what you think – or what you feel? Your brain should be in control, telling you what to do (positive functional commands), rather than allowing your emotions to distract you by imposing how you feel onto your behavior. Your emotions may be based on concern with results and an anxiety related to negative anticipation.
They may have been produced by what Shakespeare called “horrible imaginings.” A focus on self will produce an exaggerated and often distorted point of view. Surely, you’ve heard or read about many athletes who’ve said, “I have a completely different perspective now.” The cause might have been a first child, a death in the family, or some other event that, first, puts the athlete’s focus beyond himself or herself. Second, it allows the athlete to see a reality with life significance beyond imaginings related to the results of an athletic event. The athlete sees priorities that result in greater understanding, more relaxed muscles and more effective performance. The complexities of life allow us to better see the simplicity of the task we face. And it helps eliminate many of the “I gotta’s” from our vocabulary.