“Goals are effective because they influence psychological states such as self-confidence, direct attention to important aspects of the task, mobilize effort, increase persistence and foster the development of new learning strategies (Gould, 1993, p. 168).”
“In essence, goal setting involves commitment and effort on the part of the coaches as well as athletes (Gould, 1993, p. 164).”
This comes from an article on kids First Soccer by Daniel Frankl, Ph.D.
In the article he discusses the following:
Elements that make effective goals
General objective goals
Specific objective goals
The planning phase
The meeting phase
The follow-up/evaluation phase
Common problems in setting goals
Here’s the full article.