- 4 Muscle repair and growth
- 5 Nitric oxide boosters (pump enhancers)
- 8 Concentration and focus (nootropics)
- 9 Fat burners
Pre workout supplements contain a wide variety of ingredients, but the general effects they aim to achieve are pretty simple: allow you to perform more reps and/or at a higher resistance level when training. Ultimately, the goal is to increase energy and motivation, support muscle repair and growth, and mobilize body fat for use as fuel.
Not sure where to start?
If you're new to pre workouts, then the best place to start is the official Best Pre Workout buyer's guide on our blog.
It takes your preferences into account, and also explains the dozens and dozens of popular ingredients inside of the pre workouts, with over one hundred sources cited!
Ingredients and uses
Rather than attempting to cover every pre-workout formula on the market, it's simpler to look at some of the ingredients most commonly found in supplements.
Many of these ingredients can be used singularly — for example, most of the world's population uses caffeine for energy — but pre-workout formulas combine multiple ingredients in an attempt to achieve optimal results. In order for supplement manufacturers to gain notoriety for producing legitimately potent or effective pre-workouts, the good companies out there, of which there are many, will craft their products based on scientific studies conducted on humans (not just lab animals!).
Only those that consistently produce favorable, healthy results should make it to market. Unfortunately, there are products formulated with questionable ingredients and shoddy research — or just research on lab mice or in vitro — that still manage slip through.
Here are some of the ingredients typically found in pre-workout supplements, sorted by their primary intended effect:
Muscle strength and endurance
The following ingredients are added to pre-workouts as power and endurance boosters, but they do not need to be taken pre workout. They accumulate and saturate in your system over time.
Manufacturers simply include many of these in their pre-workouts to ensure that you are indeed getting them, and because it's convenient:
Beta-alanine is a non-essential amino acid that serves one purpose: to improve carnosine uptake by muscle tissue. On its own, beta-alanine won't do anything to enhance your workout, but it will improve carnosine's ability to prevent acid build-up in working muscle tissue.
Beta-alanine is also well known for causing a tingling sensation in the skin. It is not toxic, but this tingling feeling annoys some individuals. We like it because it alerts us to the fact that the pre-workout is in our system and it's time to start getting after it.
Creatine is an amino acid compound that aids in overall cellular energy production, but is especially concentrated in muscle tissue. It's primarily used to support short bursts of high-intensity energy, but post-workout, it has been found to aid in muscle growth.[2,3]
Typically, you want to take 5g of creatine monohydrate each and every day - it doesn't matter when or how - just get it in. Pre-workout is a convenient time to take it, but there is no absolute timing requirement.
Betaine, also known as trimethylglycine, or TMG, is a naturally occurring compound that supports the liver and plays a role in the development of new cells. It also naturally stimulates carnitine production, which is the primary reason for its inclusion in supplements. In addition, some studies have shown increased ability to do reps and lift weights after supplementation.[4,5]
Muscle repair and growth
Branched-chain amino acids (BCAAs)
BCAAs are four of the nine essential amino acids: They're are a daily requirement and can only be obtained through food. These four compounds are unique in that they support exercise and muscle function, aiding in glucose uptake and muscle protein synthesis.
Glutamine is a primary fuel source for working muscle. It's another amino acid that does not contribute to muscle growth on its own, but does so indirectly by stimulating the production of cortisol. Cortisol moderates stress hormone production and aids the immune system, allowing damaged muscle tissue to heal at a faster rate.[7,8]
Carnitine - LCLT
L-carnitine L-tartrate is a sub-compound of l-carnitine that functions as an antioxidant, supports muscle repair, and helps to reduce soreness after exercise.
Nitric oxide boosters (pump enhancers)
The following ingredients promote more nitric oxide (NO) production in your bloodstream. To a limit, extra NO creates vasodilation, which is the widening of your veins, which, in turn, improves blood flow and nutrient delivery, temporarily giving you increases in strength and power.
You do not ingest NO. You take amino acids and other ingredients such as those below, which then boost NO levels.
These benefits, on their own, will not make you bigger in the long run. With the proper workout, they will get you additional sets and reps, promoting more muscle tearing. It is then up to you to eat properly in order to turn those reps into true gains.
Arginine is an amino acid that's used a variety of ways throughout the body, but is present in supplements because it's a precursor of nitric oxide. Citrulline is the amino acid that arginine is synthesized from, and has become popular in supplements as uptake of arginine has been shown to increase when taken as a citrulline supplement.[9,10]
In the early 2010s, a common form of arginine was AAKG, or arginine alpha ketoglutarate. This has recently been replaced by L-citrulline and the ingredients below, due to their ability to better improve NO production better than L-arginine on its own.
Agmatine is a fairly new supplement that serves the same function as arginine, but is believed to have superior uptake as the carboxylic acid has been removed.
Carnitine - GPLC
Carnitine directly supports cellular energy production. It has several sub-compounds that further support good health and energy, but glycine propionyl-L-carnitine (GPLC) is the most relevant to pump enhancement as it provides a significant nitric oxide boost to the muscles.
Nitrates are a potent vasodilator — they increase blood flow to the muscles. You'll see nitrates in various compounds designed to enhance their effects even further. Some popular examples are potassium nitrate and creatine nitrate.
Glycerine (aka glycerin) is more well known as a soap ingredient (and possibly for getting a lot of radio play, if you grew up in the '90s), but it's also used by some bodybuilders as a pump enhancer because it's extremely effective at hydrating muscle tissue. Glycerol monostearate is simply a compound of glycerine that is commonly used as a sweetener and preservative, in addition to providing the bodybuilding benefits of glycerin (which is normally flavorless).
Unlike the above ingredients, glycerol does not work via nitric oxide production. Instead, it's all about drawing water into your muscle tissue. (Think of glycerol like a sponge.) So if you have a pre-workout supplement featuring this ingredient, take it with plenty of water — 20 oz. or more.
Caffeine is the most widely used stimulant on Earth. As you're likely already aware from experience, the primary purpose is a rapid feeling of energy and reduction of fatigue. Caffeine is sometimes included in supplements as a fat burner because it has a very mild effect in heightening metabolism. It is not a significant contributor to weight loss.
Yerba mate contains caffeine, but also theobromine and theophylline. Some believe yerba mate provides a steadier, less "jittery" and energetic feeling than other forms of caffeine.
Check it out
Synephrine and yohimbe, in the "Fat Burner" section below, are also added to pre-workout supplements for their energy-enhancing properties.
B-vitamin complex — the entire range of B vitamins — won't give you direct energy in the way a stimulant will. But most of them are vital in processing your food into cellular energy.
Taurine is an amino acid that's vital to digestion and muscle function. It's believed to provide energy (largely because it's heavily advertised for that purpose and is a component of many energy drinks). It should be noted that in those beverages, taurine is often accompanied by large doses of caffeine, making it unclear how much it actually contributes to feeling energetic. Like the B-vitamin complex, however, taurine is necessary for proper digestion. Studies have shown that taurine is regulates cell volume. It optimizes muscle cell hydration, which in turn promotes anabolism and improves muscle function.
Tyrosine is an amino acid primarily needed for protein synthesis. It has also been shown to reduce feelings of fatigue in situations of high stress and to mitigate stress hormone levels. However, it hasn't been shown to have an effect on lower, more normal levels of day-to-day stress.
Concentration and focus (nootropics)
Choline (vitamin Bp)/DMAE
Choline is part of the B-vitamin complex (which as a whole is vital to brain and central nervous system function) and is a daily nutritional requirement. DMAE is a choline precursor, and in addition to providing nutritionally vital choline, it's shown some promise as an enhancer of cognitive function.
Yet another amino acid, theanine, which is commonly found in tea, reduces stress hormones and increases alpha wave activity in the brain.In supplements it's very frequently paired with caffeine as several studies have demonstrated they complement and enhance each other's beneficial effects.[19,20]
Some studies have shown that the herb ginkgo biloba not only improves attention and focus, but also demonstrates promise as a treatment for dementia symptoms. Studies on the effects of gingko biloba on attention have concluded it makes no difference whatsoever. The facts may still be unclear, but there's enough scientific and anecdotal evidence that it may be worth a try to see if you feel gain any personal benefits from it. Plus, gingko biloba is very inexpensive. Note that you should take it for about a month before you will see any benefits.
Vinpocetine is a periwinkle plant extract that's used in some pre-workout formulas as a vasodilator, but it's also promoted and sold as a focus enhancer. This is largely based on a series of medical studies showing improvement in patients with various cerebral impairments and diseases, and one study indicating improvement in short-term memory after supplementation. While there's still little in the way of supplementation studies specifically geared to memory improvement and concentration in humans, the early results are interesting and studies, up to this point, seem to concur that long-term usage is safe.
Carnitine - ALCAR
Acetyl L-carnitine (ALCAR) is the sub-compound of carnitine that fights fatigue and improves focus. It's also good for athletic endurance.
Green tea extract
The catechins and EGCg in green tea extract have shown some promise for weight loss in early studies, but the product is new and there are not enough conclusive human studies. Regardless of its uncertain status, you'll see green tea extract included as an ingredient in products that promise to burn fat.
Hordenine is a stimulant that affects the central nervous system, and used to promote the production of norepinephrine. Norepinephrine is believed to help mobilize fat for use as energy and also slow digestion, which can reduce appetite. This is entirely based on conjecture since the hormone is a lipolytic. At present, no studies actually show that supplementation contributes to fat loss.
Capsaicin and cayenne pepper extracts
Capsaicin is what gives chili peppers their heat, and it has also been shown to slightly raise metabolism. Capsaicin is sometimes listed in supplement ingredients as "cayenne pepper extract."
MCT (medium-chain triglyceride) oil is a saturated fat extracted from coconut and palm oils. MCT oils can't actually be stored as body fat, but rather, it's sent immediately to the liver for use as energy. Despite not adding any calories, it has a similar feel in the mouth as other saturated fats and is sometimes used to curb fat cravings.
Synephrine is an extract of bitter orange. It became popular as a supplement additive when ephedrine was banned. Synephrine has been shown to raise metabolism. However, in one animal study, when combined with large doses of caffeine, the fat burner had some dangerous side effects, such as seizures, breathing difficulties, and feelings of agitation. Supplements that contain synephrine typically include a warning against simultaneously consuming caffeine.
Yohimbe (or yohimbine) is extracted from the bark of a tree found in western Africa. It has shown some promise in inhibiting the retention of body fat, in more than one study. Results vary greatly with cultivation methods. One FDA study found that many yohimbe products on the market did not actually contain the compound derived from tree bark used in weight loss studies.[27,28]
Pre-workout formulas most commonly come in a powder form designed for mixing into a shake, water, or fat-free milk. Ingredients sold individually may come in a caplet or powder, which allows greater freedom in dosing.
We prefer to drink our pre-workouts because they're typically tasty and more cost-effective than pills. Some of the best pre-workouts have a lot of ingredients, which would make for some extremely large pills.
While supplement manufacturers are required to disclose their ingredients profile (see product labels), they're not obligated to disclose amounts. If you plan to use products with ingredients that can have negative or harmful side effects, such as caffeine and synephrine, it's best to purchase your pre-workouts from a manufacturer with an "open label policy," which specifies the exact amount each ingredient is used in the production process.
Unfortunately, these are still relatively rare in pre-workout formulas since some manufacturers use phrases like "proprietary formula" to keep their competitors from duplicating their secret recipes. Some companies just don't want you to know the energy boost in their pre-workout simply comes from mega-doses of caffeine. A reputable company — and there are many — will reveal their ingredients voluntarily.
The FDA does not do much to verify the efficacy of supplements or whether labeling claims are true. It usually takes independent studies and a solid body of user reviews to determine when a supplement or ingredient has the advertised effect. This has been a particular problem in fat burning products where supposed "wonder supplements," like acai berry and raspberry ketones, have turned out to be duds.
It's best to speak to a doctor before making any major changes in diet or supplementation, especially if you are on prescription medications. Pre-workout supplements can contain ingredients that have contraindications with certain medicines.
Potential side effects can vary widely depending on the ingredients.
Any product that contains stimulants may have side effects associated with consuming too much sugar or caffeine — feeling nervous or jittery, inability to sleep, gastrointestinal problems, elevated heart rate, and tremors. Addiction and dependency are also a possibility with any stimulant.
The FDA does not regulate pre-workout supplements. Several stimulants, such as ephedra and DMAA, have been banned after causing a rash of documented health problems, but the FDA generally limits itself to removing products from the market that contain illegal substances. This is important to know as there are many legal and healthy substances that when taken in excess can have toxic side effects. In fact, most vitamin types can cause toxicity if you take too much.
Ephedra has been banned in the United States since 2004 and DMAA has been banned since 2013. While you're not likely to run into ephedra at this point, it can take a year or more for banned products to be fully purged — specifically those sold on the web. You won't find them at your local GNC, but once word gets out that a substance is going to be banned, it's not unusual for fans to hoard cases.
In recent years, two products from USPLabs (Jack3d and OxyElite) received a lot of press for containing DMAA. Prior to the ban, however, there were actually over 100 workout products from a wide range of manufacturers that still contained the compound.
This is another example why an open-label policy is advantageous. In addition to the dangers associated with amphetamine use, a product that is legal to sell may still contain substances that can cause a professional athlete or bodybuilder to fail a doping test.
Where to buy
You can find a full range of pre-workout supplements here at PricePlow and often at 30% to 50% off of retail prices. Let our comparison shopping engine do the work so that you can get back to your workout.
- Artioli, G, et. al; Medicine and Science in Sports and Exercise; "Role of beta-alanine supplementation on muscle carnosine and exercise performance;" June 2010
- Rawson, ES, et. al; Journal of Strength and Conditioning Research; "Effects of creatine supplementation and resistance training on muscle strength and weightlifting performance;" November 2003
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- Trepanowski, JF, et. al; Journal of Strength and Conditioning Research; "The effects of chronic betaine supplementation on exercise performance, skeletal muscle oxygen saturation and associated biochemical parameters in resistance trained men" December 2011
- Cholewa, JM, et. al; Journal of the International Society of Sports Nutrition; "Effects of betaine on body composition, performance, and homocysteine thiolactone;" August 2013
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- PubChem; "Compound Summary for Glycerol;" 2014
- Hernandez, A, et. al; The Journal of Physiology; "Dietary nitrate increases tetanic [Ca2+]i and contractile force in mouse fast-twitch muscle;" August 2012
- Westerterp-Plantenga, MS, et. al; Obesity Research; "Body weight loss and weight maintenance in relation to habitual caffeine intake and green tea supplementation;" July 2005
- Laquale, KM; Bridgewater State College; "B-complex vitamins' role in energy release;" 2006
- Lourenco, R, et. al; Nutricion Hospitalaria; "Taurine: a conditionally essential amino acid in humans? An overview in health and disease;" November-December 2002
- Young, S, et. al; Journal of Psychiatric Neuroscience; "L-Tyrosine to alleviate the effects of stress?;" May 2007
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- Vuong, QV, et. al; Critical Reviews in Food Science and Nutrition; "Epidemiological evidence linking tea consumption to human health: a review;" 2014
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