In the 1970s and 1980s, the East German government planned to win as many Olympic metals as it could, even if came at a great personal cost for its athletes.

Shot putter Heidi Krieger was doped without her knowing it. Her trainers told her the pills and shots were natural vitamins and supplements. The drugs masculinized Heidi to such an extent that she later would decide to undergo a sex change operation to become Andreas Krieger.

"I still say today that they killed Heidi," Krieger told the BBC in a recent interview. "It's difficult to say whether I would be Heidi today or not but I could have decided on my own... I was thrown out of my gender."

"I felt much more attracted to women and just felt like a man. But I knew I was not lesbian," Krieger told CNN.

In the 1970s and 1980s, the German Democratic Republic was one of the most successful Olympic Games nations. An estimated 10,000 young East German athletes were affected by performance-enhancing drugs during that time period, CNN reports.

The female victims of East German doctors later testified that their pubic hair had spread to their chests, their voices had deepened, and their menstrual cycle had fallen out of rhythm.

Performance enhancing drugs had a profound effect on the young women because they took them during puberty, when the reproductive system is undergoing rapid changes and being fine-tuned by a delicate balance of hormones. Female athletes were so masculinized and displayed such aggressive behavior, that the International Olympic Committee responded by initiating its first drug testing programs in the 1970s.

Krieger is now married and runs an army surplus store. He says he has taken his life into his own hands and does not want to be seen as a victim, CNN reports.

The physiological changes that proceeded Krieger's sex change represent some of the more pronounced effects of dangerous performance-enhancing drugs. The United States Doping Agency provides up-to-date information on the side-effects of some of the most common performance-enhancing drugs.

Anabolic agents, including steroids, are used medically to treat delayed puberty, certain types of impotence, and muscle wasting caused by HIV infection and similar diseases. But steroid abuse can lead to a number of side effects. The most common side-effects of anabolic steroids include acne, male pattern baldness, and liver damage. When used it children, steroids can lead to stunted growth and disruption of puberty. Psychologically, steroid abuse can lead to increased aggressiveness, commonly referred to as "roid rage."

For men, steroid abuse can lead to breast development, shrinking of the testicles, impotence, and reduced sperm production. Young women abusing steroids face deepening of the voice, breast development cessation, hair growth on the face, stomach, and upper back, enlarged clitoris, and abnormal menstrual cycles.

All of those side effects vary on an individual basis, and may be temporary or permanent depending on the case.