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* [[Caffeine]] is now one of the most common ingredients, found in one study to be in 86% of the bestselling pre-workout supplements.<ref name=":4" /> Caffeine is a popular ingredient in pre-workout because it increases alertness, mental concentration, and energy.<ref>{{Cite web|url=https://medlineplus.gov/caffeine.html|title=Caffeine|website=medlineplus.gov|access-date=2020-04-03}}</ref> Related compounds such as [[theobromine]] (sometimes as "cocoa extract") may also be used.<ref>Kennedy M. Effects of Theophylline and Theobromine on exercise performance and implications for competition sport: A systematic review. ''Drug Test Anal''. 2020 Nov 13. {{doi|10.1002/dta.2970}} {{pmid|33188564}}</ref>
* [[Caffeine]] is now one of the most common ingredients, found in one study to be in 86% of the bestselling pre-workout supplements.<ref name=":4" /> Caffeine is a popular ingredient in pre-workout because it increases alertness, mental concentration, and energy.<ref>{{Cite web|url=https://medlineplus.gov/caffeine.html|title=Caffeine|website=medlineplus.gov|access-date=2020-04-03}}</ref> Related compounds such as [[theobromine]] (sometimes as "cocoa extract") may also be used.<ref>Kennedy M. Effects of Theophylline and Theobromine on exercise performance and implications for competition sport: A systematic review. ''Drug Test Anal''. 2020 Nov 13. {{doi|10.1002/dta.2970}} {{pmid|33188564}}</ref>


* [[Methylhexanamine]], also known as DMAA, is another stimulant which was widely used for some time as an alternative or supplement to caffeine.<ref>{{Cite journal | author = Center for Food Safety and Applied Nutrition |date=2020-02-04|title=DMAA in Products Marketed as Dietary Supplements|url=https://www.fda.gov/food/dietary-supplement-products-ingredients/dmaa-products-marketed-dietary-supplements|journal=FDA|language=en}}</ref> The FDA has warned that DMAA "is known to narrow the blood vessels and arteries, which can elevate blood pressure and may lead to cardiovascular events ranging from shortness of breath and tightening in the chest to heart attack". DMAA is also considered a prohibited stimulant by the United States Anti-Doping Agency.<ref>{{Cite web|url=https://www.usada.org/dietary-supplements/athlete-advisory-methylhexaneamine-and-dietary-supplements/|title=Athlete Advisory - Methylhexaneamine And Dietary Supplements|date=2011-06-16|website=U.S. Anti-Doping Agency (USADA)|language=en-US|access-date=2020-04-03}}</ref> Following the widespread banning of DMAA, it has in some cases been replaced by similar compounds such as [[1,3-Dimethylbutylamine|DMBA]], [[tuaminoheptane]] or [[N,alpha-Diethylphenylethylamine|DEPEA]].
* [[Methylhexanamine]], also known as DMAA, is another stimulant which was widely used for some time as an alternative or supplement to caffeine.<ref>{{Cite journal | author = Center for Food Safety and Applied Nutrition |date=2020-02-04|title=DMAA in Products Marketed as Dietary Supplements|url=https://www.fda.gov/food/dietary-supplement-products-ingredients/dmaa-products-marketed-dietary-supplements|journal=FDA|language=en}}</ref> The FDA has warned that DMAA "is known to narrow the blood vessels and arteries, which can elevate blood pressure and may lead to cardiovascular events ranging from shortness of breath and tightening in the chest to heart attack". DMAA is also considered a prohibited stimulant by the United States Anti-Doping Agency.<ref>{{Cite web|url=https://www.usada.org/dietary-supplements/athlete-advisory-methylhexaneamine-and-dietary-supplements/|title=Athlete Advisory - Methylhexaneamine And Dietary Supplements|date=2011-06-16|website=U.S. Anti-Doping Agency (USADA)|language=en-US|access-date=2020-04-03}}</ref> Following the widespread banning of DMAA, it has in some cases been replaced by similar compounds such as [[1,3-Dimethylbutylamine|DMBA]], [[tuaminoheptane]] or [[N,alpha-Diethylphenylethylamine|DEPEA]].<ref>Cohen PA, Travis JC, Keizers PHJ, Deuster P, Venhuis BJ Four experimental stimulants found in sports and weight loss supplements: 2-amino-6-methylheptane (octodrine), 1,4-dimethylamylamine (1,4-DMAA), 1,3-dimethylamylamine (1,3-DMAA) and 1,3-dimethylbutylamine (1,3-DMBA), ''Clinical Toxicology'' 2018; 56(6): 421-426. {{doi|10.1080/15563650.2017.1398328}}</ref>


* [[Carbohydrate]]s are usually present, often in a mix of simple [[sugar]]s like [[glucose]] and more complex [[oligosaccharide]]s such as [[maltodextrin]] which are supposed to provide more sustained energy. These are used both to provide a sweet taste and fuel for exercise, though evidence for whether they actually enhance exercise performance is mixed.<ref>{{cite journal | vauthors = Outlaw JJ, Wilborn CD, Smith-Ryan AE, Hayward SE, Urbina SL, Taylor LW, Foster CA | title = Effects of a pre-and post-workout protein-carbohydrate supplement in trained crossfit individuals | journal = SpringerPlus | volume = 3 | pages = 369 | pmid = 25110627 | doi = 10.1186/2193-1801-3-369 }}</ref><ref>{{cite journal | vauthors = Maroufi K, Razavi R, Gaeini AA, Nourshahi M | title = The effects of acute consumption of carbohydrate-protein supplement in varied ratios on CrossFit athletes' performance in two CrossFit exercises: a randomized cross-over trial | journal = The Journal of Sports Medicine and Physical Fitness | date = December 2020 | pmid = 33314886 | doi = 10.23736/S0022-4707.20.11774-2 }}</ref>
* [[Carbohydrate]]s are usually present, often in a mix of simple [[sugar]]s like [[glucose]] and more complex [[oligosaccharide]]s such as [[maltodextrin]] which are supposed to provide more sustained energy. These are used both to provide a sweet taste and fuel for exercise, though evidence for whether they actually enhance exercise performance is mixed.<ref>{{cite journal | vauthors = Outlaw JJ, Wilborn CD, Smith-Ryan AE, Hayward SE, Urbina SL, Taylor LW, Foster CA | title = Effects of a pre-and post-workout protein-carbohydrate supplement in trained crossfit individuals | journal = SpringerPlus | volume = 3 | pages = 369 | pmid = 25110627 | doi = 10.1186/2193-1801-3-369 }}</ref><ref>{{cite journal | vauthors = Maroufi K, Razavi R, Gaeini AA, Nourshahi M | title = The effects of acute consumption of carbohydrate-protein supplement in varied ratios on CrossFit athletes' performance in two CrossFit exercises: a randomized cross-over trial | journal = The Journal of Sports Medicine and Physical Fitness | date = December 2020 | pmid = 33314886 | doi = 10.23736/S0022-4707.20.11774-2 }}</ref>

Revision as of 19:17, 28 December 2020

Pre-workout is a dietary supplement used by athletes and weightlifters to enhance athletic performance.[1] It is taken to increase endurance, energy, and focus during a workout.[1] Pre-workout supplements contain a variety of ingredients such as caffeine and creatine, ranging by product.[2] It can be taken in a variety of forms including capsules and powder.[3] The first pre-workout entered the market in 1982, and since then they have grown in popularity.[4] Some pre-workouts contain ingredients linked to adverse effects.[2] Although these products are not banned, the Food and Drug Administration (FDA) warns consumers to be cautious when consuming pre-workout.[5]

History

In 1982, Dan Duchaine formulated the first pre-workout, called Ultimate Orange, in Venice, California. Ultimate Orange quickly became popular among bodybuilders.[4]

Between the late 1990s and early 2000s, consumers alleged that an active ingredient in Ultimate Orange, called ephedra, caused high blood pressure, strokes, seizures, cardiac arrhythmia, and heart attacks.[2]

In the early 2000s, supplement companies created more potent forms of pre-workout that caused the blood vessels to enlarge temporarily, giving lifters a better “pump."[2] These more potent supplements are called Arginine AKG, Arginine Malate, and Citrulline.[2]

In 2005, chemist Patrick Arnold formulated a pre-workout called Jack3d, which contained a new ingredient called DMAA (dimethylamylamine).[6] Jack3d quickly gained notoriety for its potency, but its high concentrations of DMAA were suspected of causing shortness of breath, chest pain, and an elevated risk of heart attacks.[2]

Jack3d was banned in 2012 by the FDA.[2]

Ingredients/ Supplements

Pre-workout supplements are available in different forms including tablets, capsules, liquids, powders, and bars.[7] A number of common ingredients are used. Some ingredients such as caffeine, creatine and β-alanine are found in nearly all pre-workout blends, but each branded product is a "proprietary blend" with an average of 18 different ingredients, the exact composition and proportions of which can vary widely between different products.[8][9]

  • Ephedrine (usually as Ephedra extract) was a common ingredient in many pre-workout supplements in the 1990s and early 2000s, sometimes in combination with caffeine and aspirin (the so-called ECA stack), however following many reports of serious side effects and some deaths, it was banned for use in supplements by the FDA in 2004 throughout the USA, and many other countries have enacted similar bans.
  • Caffeine is now one of the most common ingredients, found in one study to be in 86% of the bestselling pre-workout supplements.[3] Caffeine is a popular ingredient in pre-workout because it increases alertness, mental concentration, and energy.[10] Related compounds such as theobromine (sometimes as "cocoa extract") may also be used.[11]
  • Methylhexanamine, also known as DMAA, is another stimulant which was widely used for some time as an alternative or supplement to caffeine.[12] The FDA has warned that DMAA "is known to narrow the blood vessels and arteries, which can elevate blood pressure and may lead to cardiovascular events ranging from shortness of breath and tightening in the chest to heart attack". DMAA is also considered a prohibited stimulant by the United States Anti-Doping Agency.[13] Following the widespread banning of DMAA, it has in some cases been replaced by similar compounds such as DMBA, tuaminoheptane or DEPEA.[14]
  • Carbohydrates are usually present, often in a mix of simple sugars like glucose and more complex oligosaccharides such as maltodextrin which are supposed to provide more sustained energy. These are used both to provide a sweet taste and fuel for exercise, though evidence for whether they actually enhance exercise performance is mixed.[15][16]
  • Protein supplements, usually in a palatable powdered form such as whey protein, are also commonly used both for flavour and as a fuel for muscle growth and recovery.[17][18]
  • Nitrate salts are often included (sometimes as "beetroot extract") for their supposed benefits for endurance exercise.[19]
  • Creatine, a natural chemical created in the kidneys and liver, is another popular ingredient in pre-workout. Creatine has been proven to improve physical performance as well as increase strength.[20]
  • β-Alanine is another very common ingredient that was found to be present in 87% of leading pre-workout formulas. Beta-alanine has been found to decrease fatigue during high-intensity exercise by increasing the muscle carnosine concentration which creates a buffer against muscle fatigue.[21]
  • Branched-chain amino acids, leucine, isoleucine and valine are commonly used for their muscle fueling properties and relief of post-workout soreness, often alongside other amino acids such as glutamine which are thought to have synergistic effects. Results from research have been mixed, and the dose contained in commercial pre-workout products is often less than an optimum effective dose.[22][23][24][25][26]
  • Citrulline is used as an alternative or supplement to arginine, and is claimed to reduce post-exercise soreness.[32]
  • Agmatine is also often used as an alternative or supplement to arginine.[33]
  • Taurine is also a common ingredient in pre-workout, and can be used as a supplement taken alone. It is similar to creatine in helping muscle hypertrophy that increases strength, endurance, reduced muscle damage, and helps with a faster recovery.[34]
  • Theanine is often used as an ingredient (sometimes as "green tea extract", though this may alternatively be used to refer to EGCG), to supposedly improve mental and physical performance, and reduce anxiety.[36][37]
  • Piperine (often as "black pepper extract") is often included both to improve absorption of other ingredients, and for its supposed ability to improve muscle recovery.[38][39]
  • Carnitine or its precursor acetylcarnitine are sometimes added to the mix for their supposed ability to enhance exercise performance and aid recovery, though evidence for these benefits is weak.[40][41]
  • Betaine is often used as an ingredient, despite limited evidence for effectiveness.[42][43]
  • Capsaicin is sometimes used as an ingredient in gelcap pre-workout formulations, both as a weight loss aid and for a supposed improvement of endurance.[48]
  • Prohormones such as CDMA and 7α-methyl-19-norandrostenedione were widely used in pre-workout formulations prior to 2014 when they were formally banned. These compounds are not anabolic agents in their own right, but are metabolised into anabolic steroids of a type which at the time were not restricted. Despite most known prohormones having now been banned, novel compounds of this type or known compounds which are not listed as ingredients, are still sometimes found in over-the-counter pre-workout products, and are a frequent cause of inadvertent drug testing failures by athletes in competition.[49]

Pre-workout Retail Supplements

Pre-workout supplements are sold in a variety of retailers. The top-selling brands of pre-workout supplements in 2019 included Pre JYM Pre Workout by JYM Supplemental Science, ENGN Shred Pre Workout by EVLUTION Nutrition, and C4 Original Pre Workout by Cellucor.[1] These brands were the top three in the overall bestseller category on leading bodybuilding informational website bodybuilding.com.[1] Some variations on common pre-workout products include creatine-free and stimulant-free options. The market size for pre-workout products was a $2.7 billion industry in 2008.[51]

Purported benefits of pre-workout

Impact on muscles

An increase in muscle endurance is primarily attributed to the large amounts of caffeine in pre-workout supplements.[52][53][54] The ingested caffeine acts as an adenosine receptor antagonist, which serves to reduce overall pain experienced by the consumer and allowing them to work for longer periods of time.[53]

Pre-workout has shown to decrease time it takes for muscles to recover from intense exercise, allowing athletes to reduce time between training sessions. The improvement in muscle recovery is associated with the branched chain amino acids (BCAAs) found in pre-workout,[55] particularly, glutamine.[56]

Other Benefits

Pre-workout has shown to make athletes feel more energetic during exercise, but the higher energy levels are based on subjective judgement and there is little quantitative proof of an increase in energy.[57] The improvement in perceived energy is associated with the large amounts of caffeine typically found in pre-workout supplements.[58]

Studies also show that the caffeine in pre-workout improves focus and alertness in athletes as observed through a decrease in reaction-time in different settings.[59][57]

Side effects

Pre-workout supplements that contain between 91–227 mg of sodium bicarbonate per pound may also cause digestive issues.[60]

Those who have taken a pre-workout supplement containing beta-alanine may also feel tingling sensations. This sensation is called paresthesia. Although this may be an uncomfortable feeling, the condition poses no threat to the body's central nervous system.[60]

Drawbacks of using pre-workout are:

  • Over stimulating.
  • Dehydration.
  • Increased blood pressure.
  • Addiction.
  • Insomnia.
  • Adrenal fatigue.
  • Drug test fail (if a competing athlete in particular sports)
  • Energy crash.[61]

Food and Drug Administration

The FDA has minimal control when regulating dietary supplements like pre-workout. Product manufacturers are responsible to verify that dietary supplements are safe for consumption.[62] Financial limitations prevent the FDA from testing dietary supplements before they enter the marketplace.[62] Once a supplement is available for sale, the FDA is responsible to document and monitor manufacturer reports of adverse effects.[5] Manufacturers are obligated to report documented adverse effects to the FDA.[5]

The FDA recommends speaking with a healthcare professional before using dietary supplements. Ingredients in pre-workout can have negative side effects or contraindications with other medications.[5] Taking dietary supplements may have life-threatening consequences if taken with pre-existing health conditions.[5] Federal laws state that a supplement does not have to be declared safe by FDA standards when labeled.[5] Most supplement businesses hire third-party companies to identify the contents of their supplement to ensure it enhances athletic performance. This also aids in assuring that a product’s labeled ingredients are free from illegal substances.[7]

References

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