Performance-enhancing substance

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Performance-enhancing substances (PESs), also known as performance-enhancing drugs (PEDs), [1] are substances that are used to improve any form of activity performance in humans.

Contents

Many substances, such as anabolic steroids, can be used to improve athletic performance and build muscle, which in most cases is considered cheating by organized athletic organizations. This usage is often referred to as doping. Athletic performance-enhancing substances are sometimes referred to as ergogenic aids. [2] [3] Cognitive performance-enhancing drugs, commonly called nootropics, [4] are sometimes used by students to improve academic performance. Performance-enhancing substances are also used by military personnel to enhance combat performance. [5]

Definition

The classifications of substances as performance-enhancing substances are not entirely clear-cut and objective. As in other types of categorization, certain prototype performance enhancers are universally classified as such (like anabolic steroids), whereas other substances (like vitamins and protein supplements) are virtually never classified as performance enhancers despite their effects on performance. As is usual with categorization, there are borderline cases; caffeine, for example, is considered a performance enhancer by some but not others. [6]

Types

The phrase has been used to refer to several distinct classes of drugs:

Anabolic steroids

Anabolic steroids are synthetically derived from testosterone and modified to have greater anabolic effects. [7] They work by increasing the concentration of nitrogen in the muscle which inhibits catabolic glucocorticoid binding to muscle. [8] This ultimately prohibits the breakdown of muscle and preserves muscle mass. [9] Examples of anabolic steroids include: oxandrolone, stanozolol and nandrolone. [7] Anabolic steroids can be taken through a transdermal method, orally, or through injection. Injectable forms of the steroid are the most potent and long-lasting. [10] In general, potential side effects include: muscle hypertrophy, acne, hypertension, elevated cholesterol, thrombosis, decreased high-density lipoproteins, altered libido, hepatic carcinoma, cholestasis, peliosis hepatitis, septic arthritis, Wilm's tumor, psychosis, aggression, addiction, and depression. [11] Potential side effects specifically in males include: male pattern baldness, oligospermia, prostate hypertrophy, testicular atrophy, and prostate cancer. [12] Potential side specifically in females include: hirsutism, uterine atrophy, amenorrhea, breast atrophy, and thickening of vocal cords (voice deepening). [12] Urine samples are tested to determine the ratio of testosterone glucuronide to epitestosterone glucuronide, which should be 3:1. Any ratio of 4:1 or greater is considered a positive test. [13] The 1988 Anti-Drug Abuse Act and 1990 Anabolic Steroid Act both deemed anabolic steroids as an illegal substance when not used for disease treatment. [10]

Stimulants

Stimulants improve focus and alertness. Low (therapeutic) doses of dopaminergic stimulants (e.g., reuptake inhibitors and releasing agents) also promote mental and athletic performance, as cognitive enhancers and ergogenic aids respectively, by improving muscle strength and endurance while decreasing reaction time and fatigue. [3] [14] [15] Stimulants are commonly used in lengthy exercises that require short bursts (e.g., tennis, team sports, etc.). [16] Stimulants work by increasing catecholamine levels and agonistic activity at the adrenergic receptors. [17] Examples of stimulants include caffeine, [2] ephedrine, methylphenidate and amphetamine. [3] [14] [15] [18] [19] Potential side effects include hypertension, insomnia, headaches, weight loss, arrhythmia, tremors, anxiety, addiction, and strokes. [20] Some stimulants are allowed in competitive sports and are widely accessible, though may also be monitored by the World Anti-Doping Agency (WADA), such as caffeine. [2] Others are banned as per the WADA (e.g., cocaine, amphetamines, ephedrine, etc.). [21] [22]

Ergogenic aids

Ergogenic aids, or athletic performance-enhancing substances, include a number of drugs with various effects on physical performance. Drugs such as amphetamine and methylphenidate increase power output at constant levels of perceived exertion and delay the onset of fatigue, [18] [19] [23] among other athletic-performance-enhancing effects; [3] [14] [15] bupropion also increases power output at constant levels of perceived exertion, but only during short-term use. [23]

Examples

  • Creatine : one of the most popular nutritional supplements, it contributes to 400 million dollars in sales globally every year. [24] It is a nonessential amino acid that helps to improve an athlete's performance during short-term, high intensity exercises such as weightlifting. [25] Supplementation of creatine increases skeletal muscle creatine levels, this boosts performance by increasing the rate at which adenosine triphosphate can be replenished from adenosine diphosphate, thereby increasing maximal power output. [24] Potential side effects include gastrointestinal cramps, weight gain, fatigue, and diarrhea. [26] Creatine is currently not recognized as a prohibited substance and can be purchased as a legal dietary supplement. [27]
  • β-hydroxy β-methylbutyrate , a metabolite of leucine also used as a supplement, has positive effects on lean muscle mass, possibly through a decrease in muscle catabolism. [28]
  • Human Growth Hormone (hGH): endogenous hormone that can help decrease fat mass while increasing lean body mass. [29] hGH is one of the most commonly used substances among professional athletes because it has a small window for detection. [29] It works by promoting the release of IGF-1, insulin-like growth factor, the release of which has anabolic effects on the body. [30] Potential side effects include: cardiomyopathy, diabetes, renal failure, and hepatitis. [31] If not prescribed by a professional, it is a banned substance in competition per WADA. [22] Despite its small window for detection, two primary methods of testing have been developed for hGH, one being an isoform test which detects changes in growth hormone structure in the blood, [32] and the markers test, which detects changes in serum protein ratios. [32]

Adaptogens

Adaptogens are plants that support health through nonspecific effects, neutralize various environmental and physical stressors while being relatively safe and free of side effects. [33] As of 2008, the position of the European Medicines Agency was that "The principle of an adaptogenic action needs further clarification and studies in the pre-clinical and clinical area. As such, the term is not accepted in pharmacological and clinical terminology that is commonly used in the EU." [34]

Actoprotectors

Actoprotectors or synthetic adaptogens are compounds that enhance an organism's resilience to physical stress without increasing heat output. Actoprotectors are distinct from other doping compounds in that they increase physical and psychological resilience via non-exhaustive action. Actoprotectors such as bemethyl and bromantane have been used to prepare athletes and enhance performance in Olympic competition. [35] [36] However, only bromantane has been placed on the World Anti-Doping Agency's banned list. [36]

Nootropics

Nootropics, or "cognition enhancers", are substances that are claimed to benefit overall cognition by improving memory (e.g., increasing working memory capacity or updating) or other aspects of cognitive control (e.g., inhibitory control, attentional control, attention span, etc.). [4] [37]

CNS agents

Painkillers

Allows performance beyond the usual pain threshold. Some painkillers raise blood pressure, increasing oxygen supply to muscle cells. Painkillers used by athletes range from common over-the-counter medicines such as NSAIDs (such as ibuprofen) to powerful prescription narcotics.

Sedatives and anxiolytics

Sedatives and anxiolytics are used in sports like archery which require steady hands and accurate aim, and also to overcome excessive nervousness or discomfort for more dangerous sports. Diazepam, nicotine, and propranolol are common examples. Ethanol, the most commonly used substance by athletes, can be used for cardiovascular improvements though has significant detrimental effects. Ethanol was formerly banned by WADA during performance for athletes performing in aeronautics, archery, automobile, karate, motorcycling and powerboating, but was taken off the ban list in 2017. It is detected by breath or blood testing. Cannabis is banned at all times for an athlete by WADA, though performance-enhancing effects have yet to be studied. Cannabis and nicotine are detected through urine analysis. [2] [38]

Blood boosters

Blood doping agents increase the oxygen-carrying capacity of blood beyond the individual's natural capacity. [39] They are used in endurance sports like long-distance running, cycling, and Nordic skiing. Recombinant human erythropoietin (rhEPO) is one of the most widely known drugs in this class. [28] [39] The Athlete Biological Passport is the only indirect testing method for detection of blood doping.

Erythropoietin

Erythropoietin, or EPO, is a hormone that helps increase the production of red blood cells which increases the delivery of oxygen to muscles. [40] It is commonly used among endurance athletes such as cyclists. [40] It functions by protecting red blood cells against destruction whilst simultaneously stimulating bone marrow cells to produce more red blood cells. [41] Potential side effects include: dehydration and an increase in blood viscosity which could result in a pulmonary embolism or stroke. [42] Per the WADA, it is a banned substance. [22] Urine samples can be tested via electrophoresis, and blood samples via indirect markers.[ example needed ] [43]

Gene doping

Gene doping agents are a relatively recently described class of athletic performance-enhancing substances. [28] These drug therapies, which involve viral vector-mediated gene transfer, are not known to currently be in use as of 2020. [28] [44]

Prohormones

Also known as anabolic steroid precursors, they promote lean body mass. [45] Once in the body, these precursors are converted to testosterone and increase endogenous testosterone. [46] The desired effects of steroid precursors however, are often not seen as they do not bind well to androgen receptors. [46] Examples of prohormones include norandrostendione, androstenediol, and dehydroepiandrosterone (DHEA). [45] These steroids have little desired effect compared to anabolic steroids, but have the same side effects. [47] Androstenedione in 2005 became classified as a controlled substance by WADA, however DHEA can still be obtained legally as an over-the-counter nutritional supplement. [48]

History

While the use of PEDs has expanded in recent times, the practice of using substances to improve performance has been around since the Ancient Olympic Games. [49] In the Olympic Games of 668 BC, Charmis had consumed a diet consisting of dried figs which was thought, at the time, to be a significant factor in winning the 200-yard stade race. [50] [39] Ancient Greek athletes at the time also incorporated substances such as wine and brandy into their training routines. [51] Stimulants derived from plants (e.g., Cola nitida, Bufotein, etc.) were used by the Roman gladiators to overcome injuries and fatigue. [52]

In the late 19th century as modern medicine and pharmacology were developing, PEDs saw an increase in use. [53] Supplements were now exclusively being used to enhance muscular work capacity. [53] The main substances being used included alcoholic drinks, caffeine, and mixtures created by the athletic trainers (e.g., strychnine tablets made of cocaine and brandy). [54]

In the 20th century, testosterone was isolated and characterized by scientists. [55] In 1941, the first record of synthesized testosterone use occurred when a horse was given testosterone which successfully improved its race performance. [56] Sports trainers soon after began advocating for testosterone use. [55] Images of bodybuilders with massive muscles began circulating which further perpetuated a desire among athletes to use testosterone. [57] [55] In 1967, the first prohibited substance list and anti-doping measures were implemented at the 1968 Olympics. [39]

In the 1980s, the main PEDs were cortisone and anabolic steroids. [58] In 1988, the United States Congress established the Anti-Drug Abuse Act to criminalize the distribution and possession of non-medical anabolic steroids. [59] In 1999, WADA was formed to address the escalating use of substances in sports, particularly after the 1998 doping scandal in cycling. [59]

Risk factors

Adolescents are the most vulnerable group when it comes to taking performance-enhancing substances. [60] This is in part due to the significance placed on physical appearance by this age group as well as feelings of invincibility combined with a lack of knowledge surrounding long-term consequences. [60] Studies have shown that the most common gendered risk factors include being an adolescent female dissatisfied with their body weight or an adolescent male who perceives larger body sizes as the ideal. [61] Having a negative body image or a history of depression can also be a significant risk factor. [61] These are further exacerbated by parental pressures surrounding appearance, media influence, and peer pressure. [60] [52]

Studies show that adolescent males who engage with fitness magazines are twice as likely to use performance-enhancing substances. [52] Adolescents who partake in competitive sports are at a particularly high risk, with those involved in gridiron football, basketball, wrestling, baseball, and gymnastics at the top. [52]

Usage in sport

In sports, the term performance-enhancing drugs is popularly used in reference to anabolic steroids or their precursors (hence the colloquial term steroids); anti-doping organizations apply the term broadly. [62] Agencies such as the WADA and United States Anti-Doping Agency try to prevent athletes from using these drugs by performing drug tests. When medical exemptions are granted they are called therapeutic use exemptions. [63] [64]

See also

Related Research Articles

In competitive sports, doping is the use of banned athletic performance-enhancing drugs (PEDs) by athletes, as a way of cheating. As stated in the World Anti-Doping Code by WADA, doping is defined as the occurrence of one or more of the anti-doping rule violations outlined in Article 2.1 through Article 2.11 of the Code. The term doping is widely used by organizations that regulate sporting competitions. The use of drugs to enhance performance is considered unethical and is prohibited by most international sports organizations, including the International Olympic Committee. Furthermore, athletes taking explicit measures to evade detection exacerbate the ethical violation with overt deception and cheating.

Bodybuilding supplements are dietary supplements commonly used by those involved in bodybuilding, weightlifting, mixed martial arts, and athletics for the purpose of facilitating an increase in lean body mass. Bodybuilding supplements may contain ingredients that are advertised to increase a person's muscle, body weight, athletic performance, and decrease a person's percent body fat for desired muscle definition. Among the most widely used are high protein drinks, pre-workout blends, branched-chain amino acids (BCAA), glutamine, arginine, essential fatty acids, creatine, HMB, whey protein, ZMA, and weight loss products. Supplements are sold either as single ingredient preparations or in the form of "stacks" – proprietary blends of various supplements marketed as offering synergistic advantages.

<span class="mw-page-title-main">Metandienone</span> Androgen and anabolic steroid

Metandienone, also known as methandienone or methandrostenolone and sold under the brand name Dianabol (D-Bol) among others, is an androgen and anabolic steroid (AAS) medication which is still quite often used because of its affordability and effectiveness for bulking cycles. It is also used non-medically for physique- and performance-enhancing purposes. It is often taken by mouth.

<span class="mw-page-title-main">Clenbuterol</span> Chemical compound which aids breathing

Clenbuterol is a sympathomimetic amine used by sufferers of breathing disorders as a decongestant and bronchodilator. People with chronic breathing disorders such as asthma use this as a bronchodilator to make breathing easier. It is most commonly available as the hydrochloride salt, clenbuterol hydrochloride.

<span class="mw-page-title-main">Trenbolone acetate</span> Chemical compound

Trenbolone acetate, sold under brand names such as Finajet and Finaplix among others, is an androgen and anabolic steroid (AAS) medication used in veterinary medicine, specifically to increase the profitability of livestock by promoting muscle growth in cattle. It is given by injection into muscle.

<span class="mw-page-title-main">Selective androgen receptor modulator</span> Class of pharmaceutical drugs

Selective androgen receptor modulators (SARMs) are a class of drugs that selectively activate the androgen receptor in specific tissues, promoting muscle and bone growth while having less effect on male reproductive tissues like the prostate gland.

The BALCO scandal was a scandal involving the use of banned performance-enhancing substances by professional athletes.

The use of anabolic steroids and performance-enhancing drugs in American football is officially prohibited by virtually every sanctioning body.

<span class="mw-page-title-main">Anabolic steroid</span> Class of drugs

Anabolic steroids, also known as anabolic-androgenic steroids (AAS), are a class of drugs that are structurally related to testosterone, the main male sex hormone, and produce effects by binding to the androgen receptor (AR). Anabolic steroids have a number of medical uses, but are also used by athletes to increase muscle size, strength, and performance.

Since their discovery, anabolic steroids (AAS) have been widely used as performance-enhancing drugs to improve performance in sports, to improve one's physical appearance, as self-medication to recover from injury, and as an anti-aging aid. Use of anabolic steroids for purposes other than treating medical conditions is controversial and, in some cases, illegal. Major sports organizations have moved to ban the use of anabolic steroids. There is a wide range of health concerns for users. Legislation in many countries restricts and criminalizes AAS possession and trade.

Growth hormones in sports refers to the use of growth hormones for athletic enhancement, as opposed to growth hormone treatment for medical therapy. Human Growth Hormone is a prescription medication in the US, meaning that its distribution and use without a prescription is illegal. There is limited evidence that GH doping improves athletic performance, although the perception that it does is common in the sporting community. Potential side effects of long term GH doping could mirror the symptoms found in sufferers of acromegaly, a disease in which the anterior pituitary gland produces excess growth hormone. These symptoms include swelling of the hands and feet, joint pain, fluid retention, and excessive sweating.

<span class="mw-page-title-main">NCAA banned substances</span> Items prohibited to U.S. collegiate student-athletes

In the United States the National Collegiate Athletic Association (NCAA), has since the 1970s been patrolling the usage of illegal drugs and substances for student-athletes attending universities and colleges. In 1999, NCAA Drug Committee published a list containing substances banned for the usage to student-athletes. Year after year it is updated and given to those students participating in college sports. If any student is caught taking any of the substances, they are subjected to suspension or even banned from participating in NCAA sports and possibly attending the university.

Doping, or the use of restricted performance-enhancing drugs in the United States occurs in different sports, most notably in the sports of baseball and football.

<span class="mw-page-title-main">Trenbolone enanthate</span> Chemical compound

Trenbolone enanthate, known by the nickname Trenabol, is a synthetic and injected anabolic–androgenic steroid (AAS) and a derivative of nandrolone which was never marketed. It is the C17β enanthate ester and a long-acting prodrug of trenbolone. Trenbolone enanthate was never approved for medical or veterinary use but is used in scientific research and has been sold on the internet black market as a designer steroid for bodybuilders and athletes.

<span class="mw-page-title-main">Ligandrol</span> Chemical compound

LGD-4033, also known by the developmental code name VK5211 and by the black-market name Ligandrol, is a selective androgen receptor modulator (SARM) which is under development for the treatment of muscle atrophy in people with hip fracture. It was also under development for the treatment of cachexia, hypogonadism, and osteoporosis, but development for these indications was discontinued. LGD-4033 has been reported to dose-dependently improve lean body mass and muscle strength in preliminary clinical trials, but is still being developed and has not been approved for medical use. The drug is taken by mouth.

The National Dope Testing Laboratory (NDTL) is a premier analytical testing & research organization established as an autonomous body under the Ministry of Youth Affairs and Sports, Government of India. It is the only laboratory in the country responsible for human sports dope testing. It is headed by Chief Executive Officer (CEO). Dr. Puran Lal Sahu is the Scientific Director of NDTL.

Pre-workout is a generic term for a range of bodybuilding supplement products used by athletes and weightlifters to enhance athletic performance. Supplements are taken to increase endurance, energy, and focus during a workout. Pre-workout supplements contain a variety of ingredients such as caffeine and creatine, differing by capsule or powder products. The first pre-workout product entered the market in 1982, and since then the category has grown in use. Some pre-workout products contain ingredients linked to adverse effects. Although these products are not regulated, the Food and Drug Administration (FDA) warns consumers to be cautious when consuming them.

The practice of doping in tennis involves the use of prohibited, performance-enhancing substances listed by the International Tennis Federation (ITF) and World Anti-Doping Agency (WADA). The practice is considered unsportsmanlike and unethical, with punishments for such offences ranging from official warnings to career bans, depending on the severity of the offence.

Doping in figure skating involves the use of illegal performance-enhancing drugs (PEDs), specifically those listed and monitored by the World Anti-Doping Agency (WADA). Figure skaters occasionally have positive doping results but it is not common. Bans can be enforced on figure skaters by the International Skating Union (ISU) and each country's individual skating federation. These bans can often be career ending due to the competitive nature of figure skating. A ban may be revoked if it can be proved that the skater tested positive for a prescribed medication. Some figure skaters will use PEDs to help with recovery time, allowing them to train harder and longer. Figure skating is an aesthetic sport that combines both athleticism and artistic licence, where weight-loss substances will have little effect on athletic performance but skaters may be perceived as more graceful and sleek, which is required for an athlete to be competitive.

References

  1. ↑ "Effects of Performance-Enhancing Drugs | USADA". May 2019.
  2. 1 2 3 4 Pesta DH, Angadi SS, Burtscher M, Roberts CK (December 2013). "The effects of caffeine, nicotine, ethanol, and tetrahydrocannabinol on exercise performance". Nutrition & Metabolism. 10 (1): 71. doi: 10.1186/1743-7075-10-71 . PMC   3878772 . PMID   24330705.
  3. 1 2 3 4 Liddle DG, Connor DJ (June 2013). "Nutritional supplements and ergogenic AIDS". Primary Care. 40 (2): 487–505. doi:10.1016/j.pop.2013.02.009. PMID   23668655. 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 ...
    Physiologic and performance effects [of amphetamines]
     •Amphetamines increase dopamine/norepinephrine release and inhibit their reuptake, leading to central nervous system (CNS) stimulation
     •Amphetamines seem to enhance athletic performance in anaerobic conditions 39 40
     •Improved reaction time
     •Increased muscle strength and delayed muscle fatigue
     •Increased acceleration
     •Increased alertness and attention to task
  4. 1 2 Frati P, Kyriakou C, Del Rio A, Marinelli E, Vergallo GM, Zaami S, et al. (January 2015). "Smart drugs and synthetic androgens for cognitive and physical enhancement: revolving doors of cosmetic neurology". Current Neuropharmacology. 13 (1): 5–11. doi:10.2174/1570159X13666141210221750. PMC   4462043 . PMID   26074739. Cognitive enhancement can be defined as the use of drugs and/or other means with the aim to improve the cognitive functions of healthy subjects in particular memory, attention, creativity and intelligence in the absence of any medical indication. ... The first aim of this paper was to review current trends in the misuse of smart drugs (also known as Nootropics) presently available on the market focusing in detail on methylphenidate, trying to evaluate the potential risk in healthy individuals, especially teenagers and young adults.
  5. ↑ Better Fighting Through Chemistry? The Role of FDA Regulation in Crafting the Warrior of the Future (Report). 8 March 2004. Archived from the original on 3 February 2016.
  6. ↑ "Caffeine and Sports Performance". Vanderbilt.edu. Archived from the original on 29 February 2012. Retrieved 4 March 2012.
  7. 1 2 Kicman AT (June 2008). "Pharmacology of anabolic steroids". British Journal of Pharmacology. 154 (3): 502–521. doi:10.1038/bjp.2008.165. PMC   2439524 . PMID   18500378.
  8. ↑ Ganesan K, Rahman S, Zito PM (2024). "Anabolic Steroids". StatPearls. StatPearls Publishing. PMID   29494025.
  9. ↑ "Performance Enhancing Anabolic Steroid Abuse in Women". www.acog.org. Retrieved 12 April 2022.
  10. 1 2 Reardon CL, Creado S (14 August 2014). "Drug abuse in athletes". Substance Abuse and Rehabilitation. 5: 95–105. doi: 10.2147/SAR.S53784 . ISSN   1179-8467. PMC   4140700 . PMID   25187752.
  11. ↑ van Amsterdam J, Opperhuizen A, Hartgens F (June 2010). "Adverse health effects of anabolic–androgenic steroids". Regulatory Toxicology and Pharmacology. 57 (1): 117–123. doi:10.1016/j.yrtph.2010.02.001. PMID   20153798.
  12. 1 2 Albano GD, Amico F, Cocimano G, Liberto A, Maglietta F, Esposito M, et al. (19 January 2021). "Adverse Effects of Anabolic-Androgenic Steroids: A Literature Review". Healthcare. 9 (1): 97. doi: 10.3390/healthcare9010097 . PMC   7832337 . PMID   33477800.
  13. ↑ Levy JL, Cabrera J, Thomas S, Brennan FH (2008). "Ergogenic Aids". The Sports Medicine Resource Manual. pp. 598–610. doi:10.1016/B978-141603197-0.10048-5. ISBN   978-1-4160-3197-0.
  14. 1 2 3 Parr JW (July 2011). "Attention-deficit hyperactivity disorder and the athlete: new advances and understanding". Clinics in Sports Medicine. 30 (3): 591–610. doi:10.1016/j.csm.2011.03.007. PMID   21658550. In 1980, Chandler and Blair47 showed significant increases in knee extension strength, acceleration, anaerobic capacity, time to exhaustion during exercise, pre-exercise and maximum heart rates, and time to exhaustion during maximal oxygen consumption (VO2 max) testing after administration of 15 mg of dextroamphetamine versus placebo. Most of the information to answer this question has been obtained in the past decade through studies of fatigue rather than an attempt to systematically investigate the effect of ADHD drugs on exercise. ... In 2008, Roelands and colleagues53 studied the effect of reboxetine, a pure NE reuptake inhibitor, similar to atomoxetine, in 9 healthy, well-trained cyclists. They too exercised in both temperate and warm environments. They showed decreased power output and exercise performance at both 18 and 30 degrees centigrade. Their conclusion was that DA reuptake inhibition was the cause of the increased exercise performance seen with drugs that affect both DA and NE (MPH, amphetamine, and bupropion).
  15. 1 2 3 Parker KL, Lamichhane D, Caetano MS, Narayanan NS (October 2013). "Executive dysfunction in Parkinson's disease and timing deficits". Frontiers in Integrative Neuroscience. 7: 75. doi: 10.3389/fnint.2013.00075 . PMC   3813949 . PMID   24198770. Manipulations of dopaminergic signaling profoundly influence interval timing, leading to the hypothesis that dopamine influences internal pacemaker, or "clock," activity. For instance, amphetamine, which increases concentrations of dopamine at the synaptic cleft advances the start of responding during interval timing, whereas antagonists of D2 type dopamine receptors typically slow timing;... Depletion of dopamine in healthy volunteers impairs timing, while amphetamine releases synaptic dopamine and speeds up timing.
  16. ↑ "Office of Dietary Supplements – Dietary Supplements for Exercise and Athletic Performance". ods.od.nih.gov. Retrieved 12 April 2022.
  17. ↑ Farzam K, Faizy RM, Saadabadi A (2022), "Stimulants", StatPearls, Treasure Island (FL): StatPearls Publishing, PMID   30969718 , retrieved 12 April 2022
  18. 1 2 Roelands B, de Koning J, Foster C, Hettinga F, Meeusen R (May 2013). "Neurophysiological determinants of theoretical concepts and mechanisms involved in pacing". Sports Medicine. 43 (5): 301–311. doi:10.1007/s40279-013-0030-4. PMID   23456493. S2CID   30392999.
  19. 1 2 Rattray B, Argus C, Martin K, Northey J, Driller M (March 2015). "Is it time to turn our attention toward central mechanisms for post-exertional recovery strategies and performance?". Frontiers in Physiology. 6: 79. doi: 10.3389/fphys.2015.00079 . PMC   4362407 . PMID   25852568. Aside from accounting for the reduced performance of mentally fatigued participants, this model rationalizes the reduced RPE and hence improved cycling time trial performance of athletes using a glucose mouthwash (Chambers et al., 2009) and the greater power output during a RPE matched cycling time trial following amphetamine ingestion (Swart, 2009). ... Dopamine stimulating drugs are known to enhance aspects of exercise performance (Roelands et al., 2008)
  20. ↑ Reardon CL, Factor RM (May 2016). "Considerations in the Use of Stimulants in Sport". Sports Medicine (Auckland, N.Z.). 46 (5): 611–617. doi:10.1007/s40279-015-0456-y. ISSN   1179-2035. PMID   26712509. S2CID   27551597.
  21. ↑ Cappelletti S, Daria P, Sani G, Aromatario M (January 2015). "Caffeine: Cognitive and Physical Performance Enhancer or Psychoactive Drug?". Current Neuropharmacology. 13 (1): 71–88. doi:10.2174/1570159X13666141210215655. ISSN   1570-159X. PMC   4462044 . PMID   26074744.
  22. 1 2 3 "The Prohibited List". World Anti-Doping Agency. Retrieved 12 April 2022.
  23. 1 2 Roelands B, De Pauw K, Meeusen R (June 2015). "Neurophysiological effects of exercise in the heat". Scandinavian Journal of Medicine & Science in Sports. 25 (Suppl 1): 65–78. doi: 10.1111/sms.12350 . PMID   25943657. S2CID   22782401. Physical fatigue has classically been attributed to peripheral factors within the muscle (Fitts, 1996), the depletion of muscle glycogen (Bergstrom & Hultman, 1967) or increased cardiovascular, metabolic, and thermoregulatory strain (Abbiss & Laursen, 2005; Meeusen et al., 2006b). In recent decennia however, it became clear that the central nervous system plays an important role in the onset of fatigue during prolonged exercise (Klass et al., 2008), certainly when ambient temperature is increased ... 5-HT, DA, and NA have all been implicated in the control of thermoregulation and are thought to mediate thermoregulatory responses, certainly since their neurons innervate the hypothalamus (Roelands & Meeusen, 2010). ... This indicates that subjects did not feel they were producing more power and consequently more heat. The authors concluded that the "safety switch" or the mechanisms existing in the body to prevent harmful effects are overridden by the drug administration (Roelands et al., 2008b). Taken together, these data indicate strong ergogenic effects of an increased DA concentration in the brain, without any change in the perception of effort. ... The combined effects of DA and NA on performance in the heat were studied by our research group on a number of occasions. ... the administration of bupropion (DA/NA reuptake inhibitor) significantly improved performance. Coinciding with this ergogenic effect, the authors observed core temperatures that were much higher compared with the placebo situation. Interestingly, this occurred without any change in the subjective feelings of thermal sensation or perceived exertion. Similar to the methylphenidate study (Roelands et al., 2008b), bupropion may dampen or override inhibitory signals arising from the central nervous system to cease exercise because of hyperthermia, and enable an individual to continue maintaining a high power output
  24. 1 2 Butts J, Jacobs B, Silvis M (23 October 2017). "Creatine Use in Sports". Sports Health. 10 (1): 31–34. doi:10.1177/1941738117737248. ISSN   1941-7381. PMC   5753968 . PMID   29059531.
  25. ↑ Kreider RB (February 2003). "Effects of creatine supplementation on performance and training adaptations". Molecular and Cellular Biochemistry. 244 (1–2): 89–94. doi:10.1023/A:1022465203458. ISSN   0300-8177. PMID   12701815. S2CID   35050122.
  26. ↑ Francaux M, Poortmans JR (December 2006). "Side effects of creatine supplementation in athletes". International Journal of Sports Physiology and Performance. 1 (4): 311–323. doi:10.1123/ijspp.1.4.311. ISSN   1555-0265. PMID   19124889.
  27. ↑ Perishable (10 March 2021). "What Do Athletes Need to Know About Creatine? | USADA" . Retrieved 12 April 2022.
  28. 1 2 3 4 Momaya A, Fawal M, Estes R (April 2015). "Performance-enhancing substances in sports: a review of the literature". Sports Medicine. 45 (4): 517–531. doi:10.1007/s40279-015-0308-9. PMID   25663250. S2CID   45124293.
  29. 1 2 Saugy M, Robinson N, Saudan C, Baume N, Avois L, Mangin P (July 2006). "Human growth hormone doping in sport". British Journal of Sports Medicine. 40 (Suppl 1): i35–i39. doi:10.1136/bjsm.2006.027573. ISSN   0306-3674. PMC   2657499 . PMID   16799101.
  30. ↑ Laron Z (October 2001). "Insulin-like growth factor 1 (IGF-1): a growth hormone". Molecular Pathology. 54 (5): 311–316. doi:10.1136/mp.54.5.311. ISSN   1366-8714. PMC   1187088 . PMID   11577173.
  31. ↑ Siebert DM, Rao AL (October 2018). "The Use and Abuse of Human Growth Hormone in Sports". Sports Health. 10 (5): 419–426. doi:10.1177/1941738118782688. ISSN   1941-0921. PMC   6116101 . PMID   29932857.
  32. 1 2 Baumann GP (April 2012). "Growth hormone doping in sports: a critical review of use and detection strategies". Endocrine Reviews. 33 (2): 155–186. doi: 10.1210/er.2011-1035 . ISSN   1945-7189. PMID   22368183.
  33. ↑ Koncic MZ, Tomczyk M (August 2013). "New insights into dietary supplements used in sport: active substances, pharmacological and side effects". Current Drug Targets. 14 (9): 1079–1092. doi:10.2174/1389450111314090016. PMID   23574283.
  34. ↑ "Reflection Paper on the Adaptogenic Concept" (PDF). European Medicines Agency Committee on Herbal Medicinal Products. 8 May 2008. Archived from the original (PDF) on 20 September 2018. Retrieved 2 September 2018.
  35. ↑ Oliynyk S, Oh S (September 2012). "The pharmacology of actoprotectors: practical application for improvement of mental and physical performance". Biomolecules & Therapeutics. 20 (5): 446–456. doi:10.4062/biomolther.2012.20.5.446. ISSN   1976-9148. PMC   3762282 . PMID   24009833.
  36. 1 2 Burnat P, Payen A, Le Brumant-Payen C, Hugon M, Ceppa F (27 September 1997). "Bromontan, a new doping agent". Lancet. 350 (9082): 963–964. doi: 10.1016/s0140-6736(05)63310-7 . ISSN   0140-6736. PMID   9314900. S2CID   34909949.
  37. ↑ Ilieva IP, Hook CJ, Farah MJ (June 2015). "Prescription Stimulants' Effects on Healthy Inhibitory Control, Working Memory, and Episodic Memory: A Meta-analysis". Journal of Cognitive Neuroscience. 27 (6): 1069–1089. doi:10.1162/jocn_a_00776. PMID   25591060. S2CID   15788121. The present meta-analysis was conducted to estimate the magnitude of the effects of methylphenidate and amphetamine on cognitive functions central to academic and occupational functioning, including inhibitory control, working memory, short-term episodic memory, and delayed episodic memory. In addition, we examined the evidence for publication bias. Forty-eight studies (total of 1,409 participants) were included in the analyses. We found evidence for small but significant stimulant enhancement effects on inhibitory control and short-term episodic memory. Small effects on working memory reached significance, based on one of our two analytical approaches. Effects on delayed episodic memory were medium in size. However, because the effects on long-term and working memory were qualified by evidence for publication bias, we conclude that the effect of amphetamine and methylphenidate on the examined facets of healthy cognition is probably modest overall. In some situations, a small advantage may be valuable, although it is also possible that healthy users resort to stimulants to enhance their energy and motivation more than their cognition. ... Earlier research has failed to distinguish whether stimulants' effects are small or whether they are nonexistent (Ilieva et al., 2013; Smith & Farah, 2011). The present findings supported generally small effects of amphetamine and methylphenidate on executive function and memory. Specifically, in a set of experiments limited to high-quality designs, we found significant enhancement of several cognitive abilities. ...

    The results of this meta-analysis cannot address the important issues of individual differences in stimulant effects or the role of motivational enhancement in helping perform academic or occupational tasks. However, they do confirm the reality of cognitive enhancing effects for normal healthy adults in general, while also indicating that these effects are modest in size.
  38. ↑ ""No need for laboratory to test for alcohol" – WADA". www.insidethegames.biz. 5 October 2017. Retrieved 13 October 2023.
  39. 1 2 3 4 Breenfeldt Andersen A, Nordsborg NB, Bonne TC, Bejder J (26 December 2022). "Contemporary blood doping—Performance, mechanism, and detection". Scandinavian Journal of Medicine & Science in Sports. 34 (1): sms.14243. doi: 10.1111/sms.14243 . ISSN   0905-7188. PMID   36229224. S2CID   252898039.
  40. 1 2 Mairbäurl H (12 November 2013). "Red blood cells in sports: effects of exercise and training on oxygen supply by red blood cells". Frontiers in Physiology. 4: 332. doi: 10.3389/fphys.2013.00332 . ISSN   1664-042X. PMC   3824146 . PMID   24273518.
  41. ↑ Bhoopalan SV, Huang LJ, Weiss MJ (18 September 2020). "Erythropoietin regulation of red blood cell production: from bench to bedside and back". F1000Research. 9: F1000 Faculty Rev–1153. doi: 10.12688/f1000research.26648.1 . ISSN   2046-1402. PMC   7503180 . PMID   32983414.
  42. ↑ Salamin O, Kuuranne T, Saugy M, Leuenberger N (15 March 2018). "Erythropoietin as a performance-enhancing drug: Its mechanistic basis, detection, and potential adverse effects". Molecular and Cellular Endocrinology. 464: 75–87. doi:10.1016/j.mce.2017.01.033. ISSN   1872-8057. PMID   28119134. S2CID   3441151.
  43. ↑ Schumacher YO, Saugy M, Pottgiesser T, Robinson N (November 2012). "Detection of EPO doping and blood doping: the haematological module of the Athlete Biological Passport". Drug Testing and Analysis. 4 (11): 846–853. doi:10.1002/dta.406. ISSN   1942-7611. PMID   22374784.
  44. ↑ John R, Dhillon MS, Dhillon S (May 2020). "Genetics and the Elite Athlete: Our Understanding in 2020". Indian Journal of Orthopaedics. 54 (3): 256–263. doi:10.1007/s43465-020-00056-z. ISSN   0019-5413. PMC   7205921 . PMID   32399143.
  45. 1 2 Delbeke FT, Van Eenoo P, Van Thuyne W, Desmet N (December 2002). "Prohormones and sport". The Journal of Steroid Biochemistry and Molecular Biology. 83 (1–5): 245–251. doi:10.1016/s0960-0760(02)00274-1. ISSN   0960-0760. PMID   12650722. S2CID   46183096.
  46. 1 2 Labrie F, Luu-The V, Martel C, Chernomoretz A, Calvo E, Morissette J, et al. (July 2006). "Dehydroepiandrosterone (DHEA) is an anabolic steroid like dihydrotestosterone (DHT), the most potent natural androgen, and tetrahydrogestrinone (THG)". The Journal of Steroid Biochemistry and Molecular Biology. 100 (1–3): 52–58. doi:10.1016/j.jsbmb.2006.03.006. hdl: 11336/71854 . ISSN   0960-0760. PMID   16797178. S2CID   11815469.
  47. ↑ Broeder CE (February 2003). "Oral andro-related prohormone supplementation: do the potential risks outweigh the benefits?". Canadian Journal of Applied Physiology. 28 (1): 102–116. doi:10.1139/h03-009. ISSN   1066-7814. PMID   12671199.
  48. ↑ Brown GA, Vukovich M, King DS (August 2006). "Testosterone prohormone supplements". Medicine and Science in Sports and Exercise. 38 (8): 1451–1461. doi: 10.1249/01.mss.0000228928.69512.2e . ISSN   0195-9131. PMID   16888459.
  49. ↑ Prendergast HM, Bannen T, Erickson TB, Honore KR (March 2003). "The toxic torch of the modern Olympic Games". Veterinary and Human Toxicology. 45 (2): 97–102. PMID   12678299.
  50. ↑ Holt RI, Erotokritou-Mulligan I, Sönksen PH (August 2009). "The history of doping and growth hormone abuse in sport". Growth Hormone & IGF Research. 19 (4): 320–326. doi:10.1016/j.ghir.2009.04.009. PMID   19467612.
  51. ↑ Conti AA (2010). "Doping in sports in ancient and recent times". Medicina Nei Secoli. 22 (1–3): 181–190. PMID   21560989.
  52. 1 2 3 4 Yager Z, O'Dea JA (March 2014). "Relationships between body image, nutritional supplement use, and attitudes towards doping in sport among adolescent boys: implications for prevention programs". Journal of the International Society of Sports Nutrition. 11 (1): 13. doi: 10.1186/1550-2783-11-13 . PMC   3986904 . PMID   24670105.
  53. 1 2 Baron DA, Martin DM, Abol Magd S (June 2007). "Doping in sports and its spread to at-risk populations: an international review". World Psychiatry. 6 (2): 118–123. PMC   2219897 . PMID   18235871.
  54. ↑ Knechtle B, Nikolaidis PT (2018). "Physiology and Pathophysiology in Ultra-Marathon Running". Frontiers in Physiology. 9: 634. doi: 10.3389/fphys.2018.00634 . PMC   5992463 . PMID   29910741.
  55. 1 2 3 Freeman ER, Bloom DA, McGuire EJ (February 2001). "A brief history of testosterone". The Journal of Urology. 165 (2): 371–373. doi:10.1097/00005392-200102000-00004. PMID   11176375.
  56. ↑ Waller CC, McLeod MD (12 October 2016). "A review of designer anabolic steroids in equine sports: Designer steroids in equine sports". Drug Testing and Analysis. 9 (9): 1304–1319. doi: 10.1002/dta.2112 . hdl: 1885/146363 . PMID   27732767. S2CID   9056906.
  57. ↑ Eidelsberg J (June 1946). "Testosterone pellet implantation". The Journal of Clinical Endocrinology and Metabolism. 6 (6): 423–425. doi:10.1210/jcem-6-6-423. PMID   20988415.
  58. ↑ National Institute on Drug Abuse. "What is the history of anabolic steroid use?". National Institute on Drug Abuse. Retrieved 5 April 2022.
  59. 1 2 Kitagawa H, Hisatsune J, Ohge H, Kutsuno S, Hara T, Masuda K, et al. (July 2021). "Implanted Port Catheter System Infection Caused by Methicillin-resistant Staphylococcus pseudintermedius ST71-SCCmec type III". Internal Medicine. 60 (14): 2337–2340. doi:10.2169/internalmedicine.5579-20. PMC   8355384 . PMID   33583884.
  60. 1 2 3 White ND, Noeun J (March 2017). "Performance-Enhancing Drug Use in Adolescence". American Journal of Lifestyle Medicine. 11 (2): 122–124. doi:10.1177/1559827616680593. PMC   6125030 . PMID   30202322.
  61. 1 2 Dandoy C, Gereige RS (June 2012). "Performance-enhancing drugs". Pediatrics in Review. 33 (6): 265–271, quiz 271–272. doi:10.1542/pir.33-6-265. PMC   4528343 . PMID   22659257.
  62. ↑ "Performance-Enhancing Drug Resources". Drug Free Sport. Retrieved 14 April 2013.
  63. ↑ "Who we are". World Anti-Doping Agency. 14 November 2013. Retrieved 3 November 2015.
  64. ↑ "U.S. Anti-Doping Agency – USADA". U.S. Anti-Doping Agency (USADA). Retrieved 3 November 2015.
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