Anabolic steroids

Testosterone plays a key role in athletic performance by stimulating protein synthesis, muscle growth, and increases in body mass. Other hormones, such as growth hormone and erythropoietin, have also been used to enhance performance by promoting muscle recovery or increasing oxygen-carrying capacity.

Anabolic steroids are synthetic derivatives of testosterone designed to increase muscle size and strength. They can also promote secondary male sex characteristics, such as increased body hair and a deeper voice.

Athletes who misuse anabolic steroids often take them in supraphysiologic doses, well beyond normal therapeutic levels. Research indicates that higher doses are associated with greater increases in muscle mass. Use is often organized using practices such as stacking (combining different steroids), pyramiding (gradually increasing and then tapering doses), or cycling (alternating periods of use and abstinence).

Anabolic steroid use extends beyond elite athletes and strength trainees. Surveys indicate that approximately 7% of male American high school seniors have used anabolic steroids. Among these users, about one-third were not involved in school-sponsored sports, and one-fourth reported that their primary motivation for using steroids was appearance enhancement rather than performance.

Efficacy and adverse effects

The primary ergogenic benefits of anabolic steroid use include:

• Increased muscle mass
• Enhanced strength
• Improved athletic performance

However, these effects depend on the athlete’s training status, dosage, and duration of use. Strength-trained athletes may experience significant gains, while novice lifters may see minimal improvements beyond natural training adaptations.

One of the primary reasons athletes and non-athletes take anabolic steroids is to increase lean muscle mass and strength. Research suggests that:

• Individuals using anabolic steroids may experience greater increases in muscle protein synthesis compared with non-users, particularly when combined with resistance training and higher doses.
• Gains in fat-free mass, strength, and performance can persist even after cessation of steroid use.
• Testosterone administration has been shown to increase lean body mass by up to 15 lbs (7 kg) over a one-year period.

However, not all weight gained from steroid use is muscle. Some increases in body weight are due to intracellular water retention, which can be mistaken for muscle growth.

While anabolic steroids can enhance performance, they come with significant health risks, including:

• Cardiovascular issues: Increased risk of heart disease, high blood pressure, and adverse changes in cholesterol levels.
• Liver damage: Particularly with oral steroids, which undergo hepatic metabolism.
• Hormonal imbalances: Suppression of natural testosterone production, leading to testicular atrophy and infertility.
• Psychological effects: Increased aggression, irritability, and mood swings.

A study by Pope et al. found that 60% of steroid users experience increased irritability and aggression. Some athletes perceive this as beneficial in contact sports, but it can create serious risks for both the user and others.

Research suggests steroid abuse may be linked to muscle dysmorphia (also known as reverse anorexia), in which users perceive themselves as small despite substantial muscle mass.

Testosterone precursors and banned prohormones

Prohormones, such as androstenedione and dehydroepiandrosterone (DHEA), are marketed as testosterone boosters but have weaker androgenic effects than anabolic steroids. Many prohormones have been banned due to their potential health risks and limited performance benefits.

The 2004 Anabolic Steroid Control Act classified several prohormones as controlled substances. Studies on their efficacy show mixed results, with some demonstrating no significant improvements in strength or muscle mass. Additionally, these supplements may contribute to hormonal imbalances and increased health risks.

It is important to note that legal status does not necessarily mean permissibility in sport. Organizations such as WADA and the NCAA maintain strict policies on banned substances, so athletes must stay up to date with the regulations that apply to their sport.

Athletes should exercise caution when considering prohormones for performance enhancement due to limited evidence supporting their effectiveness and the potential for adverse effects.

Human chorionic gonadotropin (HCG)

HCG is sometimes used in weight loss interventions, but it has not been proven effective for inducing weight loss. In these cases, the primary factor contributing to weight reduction is caloric restriction, not the direct effects of HCG.

Efficacy of HCG in males

• HCG has no performance-enhancing benefits for females.
• In males, it is anecdotally cited as useful for those taking anabolic steroids.
• When injected into men, HCG can increase testicular testosterone production, leading to nearly double testosterone levels within four days after a large intramuscular injection.
• HCG mimics luteinizing hormone (LH), stimulating Leydig cells in the testicles to produce testosterone.

Adverse effects of HCG

• HCG is injected under the skin or into muscle.
• Common side effects include pain, swelling, and tenderness at the injection site.
• Limited research exists on long-term adverse effects.
• Some studies have linked HCG use to elevated blood pressure and abnormal blood clot formation.

Insulin

Insulin is an anabolic hormone that regulates blood glucose and facilitates amino acid uptake into cells. Because of these anabolic properties, insulin is sometimes misused by bodybuilders.

Efficacy of insulin in performance enhancement

• When naturally secreted, insulin plays a key role in muscle glucose regulation.
• Recombinant insulin has been misused by athletes to increase protein synthesis.
• There is no scientific evidence that insulin use enhances strength or performance in non-diabetic individuals.

Adverse effects of insulin misuse

• Hypoglycemia (low blood sugar) is the most immediate and dangerous side effect.
• Other risks include:
  • Coma or death from severe hypoglycemia.
  • Development of insulin-dependent diabetes from long-term misuse.

Human growth hormone (HGH)

HGH is a protein hormone secreted by the anterior pituitary gland that has anabolic and metabolic functions.

Effects of HGH

• Stimulates bone and skeletal muscle growth.
• Regulates blood glucose levels.
• Enhances fat metabolism.

Efficacy of HGH use in athletics

• Studies show positive changes in body composition (increased lean tissue, reduced fat).
• HGH does not significantly increase muscle strength or power.
• Some athletes use HGH because it is difficult to detect in urine tests.

Adverse effects of HGH misuse

• Organ enlargement and metabolic abnormalities.
• Increased risk of cardiovascular disease.
• Excessive HGH secretion can lead to acromegaly (abnormal bone growth in hands, feet, and face).

Erythropoietin (EPO)

EPO is a hormone produced by the kidneys that stimulates red blood cell production.

Efficacy of EPO in endurance athletes

• Increases hematocrit and hemoglobin levels.
• Improves oxygen transport to muscles.
• Enhances aerobic performance and time to exhaustion.

Adverse effects of EPO use

• Thickening of the blood (increased viscosity), leading to:
  • Increased risk of heart attacks and strokes.
  • Pulmonary embolism (blood clots in the lungs).
• Dehydration further compounds cardiovascular risks.

Beta-adrenergic agonists

Beta-agonists, such as clenbuterol, were originally developed for asthma treatment but have been used to enhance muscle growth and fat loss.

Efficacy of beta-agonists

• Increase lean muscle mass and reduce subcutaneous fat.
• Studies have not consistently supported ergogenic effects.

Adverse effects of beta-agonists

• Side effects may include:
  • Tremors
  • Dizziness
  • Insomnia
  • Increased heart rate
  • Elevated blood pressure

Beta-blockers

Beta-blockers are drugs that block beta-adrenergic receptors, preventing epinephrine and norepinephrine from binding. They are often used for cardiovascular conditions but have also been misused in sports that require steady hand control (e.g., shooting, archery).

Efficacy of beta-blockers in sports

• Improve fine motor control and accuracy.
• Reduce anxiety and heart rate, which may benefit precision sports.

Adverse effects of beta-blockers

• Reduced cardiovascular response to exercise, impairing endurance.
• Prolonged hypoglycemia, bradycardia, and heart block.
• Increased perception of fatigue and exertion.