Chapter 16: Performance-Enhancing Drugs

The use by athletes of performance-enhancing drugs, also referred to as ergogenic or energy-producing drugs, is of concern for several reasons.  Athletes are often role models for young people, and the use of drugs goes against our tradition of fair play in sports.  In addition, athletes may risk their health or even their lives by using performance-enhancing drugs.

Reports of the use of drugs in athletics go back thousands to years to the ancient Greeks and Aztecs.  In the nineteenth and early twentieth century, athletes used stimulants such as caffeine, cocaine, and even strychnine in an effort to improve their performance.  Athletic use of stimulants appears to have increased and spread to most sports with the use of amphetamines during the 1950’s and 1960’s. International drug testing began in the late 1960’s, but problems persist as researchers develop new forms of steroids and other drugs as well as new strategies to help athletes avoid detection.

Stimulants such as amphetamines and caffeine have been shown to increase work output and to mask the effects of fatigue. Most athletes perform slightly better when using stimulants, but it isn't clear if the improvement comes from actual increases in physical ability or the psychological effects of the drugs.  Stimulant use is banned for competition, but some athletes have continued to use stimulants during training, despite the dangers of injury, overexertion and dependence.

Anabolic steroids are capable of increasing muscle mass and probably strength, although it has been difficult to separate the psychological stimulant-like effect of these drugs from the physical effects they may have on muscles.  There are also difficulties in researching the effects of steroids because it would be dangerous and unethical to give test subjects the large doses or combinations of steroids typically administered by steroid-using athletes.  Anabolic steroids can produce a variety of dangerous and sometimes irreversible side effects, including liver cysts, baldness, atrophy of the testes in men, and increased facial hair in women.  Steroids are listed on Schedule III, and all nonmedical use is banned.  Other hormonal manipulations are also potentially dangerous, and it is unclear if substances such as human growth hormone actually improve athletic performance.

Beta-2 agonists are another class of banned ergogenic drugs.  They have sympathomimetic effects on the bronchi of the lungs and are sometimes used in treating asthma.  Animal studies have shown a possible effect on muscle mass, but there is no evidence that they improve athletic performance.

Creatine is a natural substance found in meat and fish.  It is sold legally as a dietary supplement and may play a role in regenerating ATP, which provides the energy for muscle contractions.  There is some evidence that use of creatine can improve strength and short-term speed in sprinting events.  However, it may actually hurt performance in longer-distance events because it tends to promote weight gain. Creatine appears relatively safe but little is known about its long-term effects.

Many other nutritional supplements are marketed to athletes and other active individuals, but there is little evidence supporting their use.  As described in Chapter 12, dietary supplements do not have to prove safety or effectiveness before being sold.