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

Exercise itself induces these same effects, so amphetamines have not been shownto make a net contribution to the physiological mechanisms which support athleticperformance. They clearly make no difference in maximal aerobic capacity, but there issome evidence for small increases in speed and the time it takes to fatigue in enduranceevents. It could be that the primary performance enhancement benefit rendered byamphetamines lies in their psychological effects as listed in Table 13-5.Table 13-5. Psychological Effects of AmphetaminesDelayed onset of the sensation of fatigueIncreased alertnessMood elevationIncreased aggressionImproved self-confidenceSuppression of inhibitionsPerhaps more so than with many drugs, the use of amphetamines is associated withdetrimental side-effects that cannot only erode athletic performance, but can also harmhealth and threaten life. These are listed in Table 13-6. Because of these side-effects andthe illegality of their use, these drugs must be avoided.230 Harmful Substances that Affect Performance