url=[http://www.usada.org/substances/effects-of-performance-enhancing-drugs/ | title=Effects of Performance-Enhancing Drugs | USADA| date=May 2019}}</ref>] are substances that are used to improve any form of activity performance in humans. A well-known example of [[cheating in sports]] involves [[doping in sport]], where banned physical performance-enhancing drugs are used by athletes and [[bodybuilding|bodybuilders]]. Athletic performance-enhancing substances are sometimes referred as '''ergogenic aids'''.<ref name="Pesta2013">{{cite journal |vauthors=Pesta DH, Angadi SS, Burtscher M, Roberts CK |date=December 2013 |title=The effects of caffeine, nicotine, ethanol, and tetrahydrocannabinol on exercise performance |journal=Nutrition & Metabolism |volume=10 |issue=1 |pages=71 |doi=10.1186/1743-7075-10-71 |pmc=3878772 |pmid=24330705 |doi-access=free }}</ref><ref name="Ergogenics">{{cite journal |vauthors=Liddle DG, Connor DJ |date=June 2013 |title=Nutritional supplements and ergogenic AIDS |journal=Primary Care |volume=40 |issue=2 |pages=487–505 |doi=10.1016/j.pop.2013.02.009 |pmid=23668655 |quote=Amphetamines and caffeine are stimulants that increase alertness, improve focus, decrease reaction time, and delay fatigue, allowing for an increased intensity and duration of training ...<br />Physiologic and performance effects [of amphetamines]<br />{{•}}Amphetamines increase dopamine/norepinephrine release and inhibit their reuptake, leading to central nervous system (CNS) stimulation<br />{{•}}Amphetamines seem to enhance athletic performance in anaerobic conditions 39 40<br />{{•}}Improved reaction time<br />{{•}}Increased muscle strength and delayed muscle fatigue<br />{{•}}Increased acceleration<br />{{•}}Increased alertness and attention to task}}</ref> Cognitive performance-enhancing drugs, commonly called [[nootropics]],<ref name="Smart drugs" /> are sometimes used by students to improve academic performance. Performance-enhancing substances are also used by military personnel to enhance combat performance.<ref>{{cite report |title=Better Fighting Through Chemistry? The Role of FDA Regulation in Crafting the Warrior of the Future |url=https://dash.harvard.edu/handle/1/8848246 |archive-url=https://web.archive.org/web/20160203110733/https://dash.harvard.edu/handle/1/8848246 |archive-date=3 February 2016 |date=8 March 2004 }}</ref>
The use of performance-enhancing drugs spans the categories of legitimate use and [[substance abuse]].
