Substances that increase the functionality of the nervous system temporarily are called stimulants. Some of the prescribed stimulants like Ritalin are used in most cases to treat narcolepsy and ADHD. These are allowed to be used and in most cases are taken under the prescription of a doctor. The stimulant drugs which can be detected by anti-doping tests cocaine, and ecstasy, not to mention methamphetamine and Ritalin, which therefore are termed as illegal for use by sportsmen and women. When used by the athletes, they reduce the rate of becoming tired and fatigued, as well as aggressiveness, alertness, and competitiveness. For immediate results to be witnessed, these drugs need to be either snorted or injected as opposed to the pills (Sefiha, 2012). Some of these legal but non-prescribed stimulants are caffeine and nicotine. However, the drugs classified as PED are far much stronger compared to the two mentioned above. Ritalin, for example, despite being prescribed by a doctor and is used to correct attention deficit disorder can help an athlete to have a clear vision and focus.