Q&A: Anabolic steroids
US baseball star Ryan Braun has been suspended for 65 games for violating the sport's anti-doping rules.
What are the banned substances and why to players continue to use them?
What are anabolic steroids?
Anabolic steroids are drugs that are usually synthesised from the male reproduction hormone testosterone.
They have been banned by many sporting bodies, including the International Olympic Committee, because of their danger to health and the potential for competitive advantage.
They are controlled substances in many countries including the US, Canada and the UK and can be taken in tablet form or injected.
Their exact effect on the body is still a matter of scientific debate.
Why do sportsmen take them?
Anabolic steroids such as Nandrolone can improve the body's capacity to train and compete at the highest level.
They reduce the fatigue associated with training and the time required to recover after physical exertion.
They also promote the development of muscle tissue in the body, with an associated increase in strength and power. This is achieved by stimulating the production of protein in the body.
However, some of the increased muscle bulk may be due to the laying down of water and minerals, so the increase in strength may not be as pronounced as expected.
What are the risks associated with anabolic steroids?
Anabolic steroids promote the growth of many tissues in the body by stimulating the release of the hormone testosterone.
By disturbing the body's equilibrium, anabolic steroids can potentially damage many of the body's major organs, particularly the liver, which has to deal with breaking down the compound.
There is also a risk of damage to the heart, which is made of muscle tissue. Anabolic steroids can lead to an expansion of the cardiac muscle, which can cause heart attacks.
The drugs also promote the growth of bones, particularly facial bones such as the jaw, and the teeth.
They have also been linked to also an increased risk of cancer.
Other side effects include the development of inappropriate sexual characteristics such as breasts in men, and facial hair in women; a deepening of the voice; baldness; male impotence.
Are all anabolic steroids detected by drugs tests?
Some sports people who take anabolic steroids escape detection because they stop taking the drugs prior to competition, giving the body time to break down the compounds.
Some also take other drugs to try and mask the presence of steroids in the body.