Effort is a conscious application of energy in a given direction. It is the fuel that makes everything go. Even the latest model Ferrari won't go an inch without gasoline. Your performance will not work without effort. The key to developing the best effort is to make sure your fuel is pure.
Pure fuel comes from intrinsic motivation, or feeling motivated from within.
Although it is good to strive for financial rewards in business and sports, and trophies look sharp on the shelves, these accumulations are never sufficient. They would perform well even if there were no external rewards because they love what they do and are already internally rewarded. Playing tennis for a parent or a coach is only partially helpful. The best soldiers in history have been the ones defending their own homes, rather than greedy mercenaries padding their bank accounts. Similarly, the performer seeking excellence should discover the inner resources needed to excel, or never expect their highest performance possible.