The Navy SEAL Physical Fitness Guide - Uniformed Services ...

Table 13-3. Physiologic Effects of Growth HormoneUnfortunately, the increase in muscle mass does not increase muscle strength asmuch as strength training. No increase in height has been seen in a fully grown person,however, hGH may increase hand, foot, jaw and body size. There is little known about theadverse effects of hGH use in the normal athlete, but the skeletal muscle growth may beabnormal and therefore the muscles may be weak. Given that hGH use is banned by themilitary, as well as the IOC, NFL, NCAA and most sports governing bodies, it should notbe used.ClenbuterolClenbuterol, a drug used by veterinarians to increase muscle mass in livestock, isbeing used by many athletes, primarily those in strength-related sports. However, increasesin muscle strength have not been shown in humans. In addition, there are numerous adverseside effects, including rapid heart rate, muscle tremors, headaches, nausea, dizziness, feverand chills. Although technically classified as a ß 2 -agonist, it is officially considered ananabolic agent by the USOC, and is thus on their list of prohibited substances.StimulantsStimulants are agents which increase arousal of the central nervous system (CNS).These agents are used medically in the treatment of various conditions, includingdepression, narcolepsy (sudden and irresistible onset of sleep), and in the treatment ofdiseases of the bronchial tubes. Athletes often abuse a number of stimulants because theythink their performance will improve. Most stimulants are banned by the military as wellas most sport governing bodies; these agents are also measured in routine random drugscreening tests. The major classes of CNS stimulants are:" Amphetamines" EphedrineIncreases muscle massIncreases fat breakdown for energyConserves blood glucose and muscle glycogen storageIncreases height in the skeletally immature individualIncreases size of hands, feet, and jawEnhances healing of musculoskeletal injuries228 Harmful Substances that Affect Performance