Performance-enhancing substances

A performance-enhancing substance is any ingested or injected compound intended to improve athletic performance. Strength and conditioning professionals group them by mechanism. Anabolic agents — testosterone and its synthetic derivatives, along with growth hormone and insulin-like growth factor — increase lean muscle mass and strength by promoting protein synthesis. Stimulants such as amphetamines, ephedrine, and caffeine act on the central nervous system to raise alertness, reduce perceived effort, and delay fatigue. Blood doping and erythropoietin (EPO) raise red blood cell count to increase oxygen delivery for endurance work. Beta-2 agonists, diuretics used for weight class manipulation or masking, and beta-blockers used to steady the hands in precision sports round out the banned categories.

Not every ergogenic aid is prohibited. Creatine monohydrate, the most researched legal supplement, increases phosphocreatine stores and improves repeated high-intensity efforts. Caffeine improves endurance and time-to-exhaustion at moderate doses. Beta-alanine buffers muscle acidity during efforts lasting roughly one to four minutes, and sodium bicarbonate serves a similar buffering role. These substances have measurable effects supported by research, which is what separates them from the large market of supplements with little evidence behind them.

The risks of banned agents are substantial and well documented. Anabolic steroid use is associated with adverse lipid changes, hypertension, left ventricular hypertrophy, liver injury with oral 17-alkylated forms, suppression of endogenous testosterone, gynecomastia in men, virilization in women, and premature epiphyseal closure in adolescents. Stimulants raise heart rate and blood pressure and can cause arrhythmias. Blood doping thickens the blood and increases clotting risk. Because dietary supplements are not reviewed for safety or purity before sale, contamination is also a real concern for drug-tested athletes.

The NSCA Certified Strength and Conditioning Specialist (CSCS) exam devotes a domain to this material. You are expected to classify the major substance categories and their mechanisms, recognize the physiological and psychological signs of use, know the documented side effects, and understand the strength and conditioning professional's ethical and legal obligation to discourage banned substances and refer athletes to qualified medical and nutrition professionals.