Doping means not only cheating by taking substances or using methods that are listed on the annual WADA List of prohibited substances and methods, but also violating any other Anti-Doping Rule of IAAF or your National Federation.
The following websites provide further information:
Health impact/side effects of Doping
Doping by using prohibited substances or methods not only threatens our sport, it also harms your health. Most of the products used as doping substances are medicines developed and used for healing bad diseases. In such cases, side effects are accepted. However, taking drugs when you are not ill means that you may suffer severe side effects but no healing effect.
Think about it and find more information here:
Effects of Doping
Principal doping substances and their side effects
Rules and Regulations
The rules and regulations that are important in connection with or in dealing with matters of Anti-Doping are the WADA Code, the IAAF Anti-Doping Regulations, the IAAF Competition Rules (in particular Chapter 3 and 4) and the codes of your National Federation or National Anti-Doping-Organisation.
Such rules and regulations also define Anti-Doping rule violations and procedures. So you should study them carefully. Be sure that you always working with the latest version of both the rules and the Anti-Doping codes as changes can occur.
In particular the WADA List of Prohibited Substance and Methods is reviewed by WADA every year. WADA revised the current version of the WADA Code. The new WADA Code will come into effect on 1 January, 2009. Have a look on the WADA website to get more information.
Nutritional supplements are very popular among athletes. It is said that they have positive impact on health and performance, however, this has never been proven by scientific study.
On the contrary, some studies show that they may have negative impact on health. In any case: by taking nutritional supplements you always take the risk of an adverse analytical finding. Previous cases have shown that athletes were tested positive due to contaminated supplements. No excuses were accepted... So, be careful!
Further information can be found here:
Questions and Answers on Supplements