Final answer:
Genetic potential is the most important predictor of success for an athlete, while the use of performance-enhancing drugs is not legitimate or ethical.
Step-by-step explanation:
The most important predictor of success for an athlete is genetic potential. Every individual has unique genetic traits that can contribute to their athletic abilities and potential. These traits can include factors such as muscle fiber composition, oxygen delivery capacity, and natural athleticism.
While coaching, practice, and other factors can play a role in an athlete's success, genetics are often considered the foundation upon which athletic abilities are built. However, it's important to note that genetic potential alone is not sufficient for success, and it must be combined with proper coaching, training, and dedication.
On the other hand, the use of performance-enhancing drugs is not a legitimate or ethical way to enhance athletic performance. These drugs are banned by most international sports organizations due to their unfair advantages and significant health risks. The use of such drugs goes against the spirit of fair competition and can have long-term negative consequences on an athlete's health.