MusclePharm Assault Review

MusclePharm Assault

Assault is the flagship pre-workout by MuscelPharm which has quickly become one of the most pervasive brands in the bodybuilding supplement industry. Although Assault does contain Caffeine, the focus is clearly on the performance/pump aspect of the product…


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Assault is the flagship pre-workout by MuscelPharm which has quickly become one of the most pervasive brands in the bodybuilding supplement industry. Although Assault does contain Caffeine, the focus is clearly on the performance/pump aspect of the product…[Skip to the Bottom Line]


Beta Alanine is a non-essential amino acid that serves as a precursor to the amino acid Carnosine, which acts as a lactic acid buffer, effectively reducing muscular fatigue. Like Creatine, Beta Alanine takes time to accumulate, but if taken over a sustained period of time, can also be an extremely effective performance enhancing supplement with a strong safety profile. One study in particular that measured the carnosine levels of sprinters found that individuals with higher muscular Carnosine levels exhibited higher power output in the latter half of a 30m sprint (because they had less lactic acid build-up). Various studies have shown that Beta Alanine supplementation increases muscular Carnosine, which improves physical performance. In particular, a 2012 study published in “Amino Acids” found that subjects who consumed 1.6 or 3.2 grams of Beta Alanine daily experienced significant increases in muscle carnosine in as little as two weeks, with the higher dose achieving a higher concentration of Carnosine. Assault contains 2g of Beta-Alanine per serving, a scientifically validated dose.


Tyrosine is a non-essential amino acid which serves as a precursor to the neurotransmitters dopamine, norepinephrine, and epinephrine, the three of which are collectively referred to as ‘catecholamines’. A 1981 study found that subjects who consumed 100mg/kg of Tyrosine experienced a significant increase in urinary catecholamine levels, but supplemental Tyrosine has failed to produce the performance enhancing effects commonly associated with increased release of catecholamine. This is because Tyrosine does not instantly get converted into noradrenaline, dopamine, or adrenaline. It forms a pool, and when there is a deficit of catecholamines, the pool is drawn from to create more. So rather than directly improving physical performance, Tyrosine has demonstrated the ability to improve aspects of cognitive function in the presence of an acute stressor (sleep deprivation, exposure to cold, and possibly exercise). In other words, Tyrosine may restore levels of dopamine, noradrenaline, and adrenaline when necessary, but does not increase them beyond normal levels.


Aspartic Acid has been touted as a performance enhancer for decades, but unfortunately, more and more studies have shown that it is far from a miracle. Preliminary evidence suggested that aspartic acid may increase the rate of ammonia removal from the blood during exercise which may allow athletes to go on for longer. However, a 1983 study, published in the “International Journal of Sports Medicine”, found that Aspartic Acid has absolutely no effect on parameters of exercise performance in men.


The active compound found in Red Beet Extract is Nitrate, which converts to Nitric Oxide in the body, a thus is said to convey performance benefits. A 2012 study, published in “Journal of the Academy of Nutrition and Dietetics”, found that increased dietary nitrate intake (in the form of Nitrate-rich whole Beetroot) improved running performance in healthy adults. A 2013 study, published in the “European Journal of Applied Physiology”, found that Nitrate supplementation (from beetroot juice) effectively elevated plasma Nitrate levels which translated to improved performance during high-intensity exercise in athletes. A 2013 Meta-Analysis, which looked specifically at 17 separate studies using doses of 300-600mg Nitrate from various sources, concluded that supplementation is associated with a moderate improvement in time to exhaustion at a given work load. It’s tough to say how much Nitrate is present in the formula for two reasons: One, it’s in the form of Red Beet Extract which is not standardized to an exact dose. Furthearmore, the amount of Red Beet Extract is concealed within the context of the Proprietary blend. MusclePharm does not disclose the exact amount of Red Beet Extract, but there is likely no shortage of Nitrates in Assault formula, especially considering the inclusion of CreNitrate, ArgNitrate, and BCAA Nitrate (all discussed below).


Dimethylglycine (DMG) was originally referred to as Vitamin B15, but since it can be produced by the body, it is technically not a vitamin at all. DMG has been alleged to enhance performance, though no studies have found this to be true, with both animal and human studies coming back negative. So while MusclePharm’s claims that DMG can enhance athletic performance are a bit tenuous, it may be useful for countering exercise-induced immune suppression, similar to Glutamine.


Dextrose is another name for Glucose, the simplest of all sugars. A 1996 study demonstrated that carbohydrates ingestion, when coupled with Creatine ingestion, was able to increase Creatine retention more than just Creatine alone. This increased absorption is the result of an spiking insulin, which pulls Creatine into muscle cells. So, while co-ingestion of simple carbohydrates with Creatine appears to improve Creatine absorption, simple carbohydrates also serve to replenish glycogen stores which are depleted (how much depends on how hard/long the workout is) during exercise. Ideally, the faster absorbing carbs are the most effective for immediate glycogen restoration and Dextrose serves as a source of “quick” energy during workouts.


The reason for the inclusion of Glycine is a bit unclear, though MusclePharm states it is because it is the simplest amino acid, “involved in the formation of proteins, peptides, glycogen, and ATP”. While this may be true, there is absolutely no evidence to suggest that Glycine supplementation has any sort of performance enhancement effect in humans or that it effectively restores ATP.


Ribose is a monosaccharide (simple sugar) which has been alleged to restore ATP post-exercise. However, a 2001 study published in the Journal of Nutrition found that supplementation with 4 grams of Ribose did nothing in the way of restoring post exercise ATP in human subjects. Furthermore, a 2003 study published in the International Journal of Sport Nutrition and Exercise Metabolism found that supplementation with 10 grams/day had no effect on anaerobic exercise capacity in healthy adult males. A 2004 study concluded that the availability of ribose does appear to be a rate-limiting factor the re-synthesis of ATP post-exercise, and that 200mg/kg Ribose was an effective dose for restoring ATP levels post-exercise. It is unclear exactly how much Ribose is included in the Assault blend, but we estimate no more than 2 grams. Unfortunately, 2 grams falls far short of what has demonstrated efficacy with regards to ATP restoration.


Cinnulin is a patented form of Cinnamon Extract standardized for ‘active’ compounds and to remove the harmful compound Coumarin. Though referring to Cinnamon extract as an “insulin mimetic” may be an exaggeration, it has demonstrated the ability to lower blood glucose in several human studies, and has drastically potentiated the effects of insulin in vitro. As mentioned above, Cinnamon contains Coumarin, a potentially liver-toxic substance which severely limits the practical application of ordinary cinnamon extract. However, Cinnulin is processed to remove this toxin, thus making effective doses practical. Given that Cinnulin can potentiate the effects of insulin, it may help shuttle Creatine in muscle cells, though there are no studies directly testing this hypothesis.


CreNitrate is created by combining Nitric Acid and Creatine to form a Creatine/Nitrate combination. The claim here is that the Nitrate portion of the compound enhances the absorption of the Creatine portion. Though this is far from substantiated, CreNitrate is effective in that it conveys both the benefits of Creatine and the benefits of Nitrate. Given that the benefits of Nitrate supplementation are discussed above (see Red Beet Extract), we will focus on Creatine in this section. Creatine has the ability to rapidly produce ATP (cellular energy) to support cellular function (as in exercise). During high intensity exercise, Creatine is used for energy which tends to spare the glycogen that would normally be used. Since lactic acid is a by-product created when glucose is burned for energy, Creatine may also indirectly reduce lactic acid build-up. Creatine has consistently been demonstrated to increase power output as well as muscle size, with maximum benefit achieved at around 8 weeks of consistent supplementation. The only issue we have with assault is that the amount of Creatine is far less than even the minimally effective dose of 2-3 grams. MusclePharm claims that CreNitrate is superior in terms of absorption, but given the lack of evidence for this claim, we’d still prefer to see more Creatine.


ArgNitrate, similar to CreNitrate is simply Arginine fused with Nitrate, conveying the benefits of both compounds. Arginine is a non-essential amino acid that acts as a precursor to Nitric Oxide. Supplement manufactures claim that, because Arginine is a precursor to Nitric Oxide, supplemental Arginine may boost Nitric Oxide levels, resulting in vasodilation. However, recent studies have found that Arginine isn’t all it’s cracked up to be. The human body is complex and, unfortunately for supplement companies, ingesting a precursor to a substance doesn’t necessarily increase the levels of that substance. A 2012 study, published in “Nutrition and Metabolism”, found that acute (one-time) L-Arginine supplementation with 6 grams did not increase plasma (blood) levels of Nitric Oxide in people with normal Asymmetric Dimethylarginine levels. Asymmetric Dimethylarginine is a compound that is chemically related to Arginine and directly interferes with the production of Nitric Oxide.

Furthermore, recent studies have questioned whether Arginine may in fact be counter-productive during exercise. A 2011, placebo controlled study, found that subjects performed worse after receiving 3700mg of Arginine Alpha-Ketoglutarate prior to resistance training. Due to the size of this study, it cannot be considered conclusive, but it certainly should warrant further studies. While most studies have failed to prove that L-Arginine supplementation increases strength, a 2012 double-blind placebo controlled study, found that supplementation with 6 grams of L-Arginine increased muscle blood volume post-workout, but did not increase intra-workout strength. While this may be disappointing for those looking to increase strength through supplementation, Arginine’s real benefits may lie in post-workout recovery, rather than intra-workout performance. More blood in the muscle’s after a workout means more nutrients to the muscle cells. However, this one study does offset the mostly negative results of multiple separate studies.


BCAA Nitrate, like CreNitrate and ArgNitrate, refers to BCAAs bound to Nitric Acid. A 2004 study conducted by the American Society for Nutritional Sciences found that BCAA requirement was significantly increased by exercise and that supplementation had “beneficial effects for decreasing exercise-induced muscle damage and promoting muscle-protein synthesis”. A second study, published in the “American Journal of Physiology-Endocrinology and Metabolism”, found that while BCAA intake did not seem to affect amino acid concentration during exercise, it did have a protein-sparing effect during recovery. If you consume a diet rich in complete proteins, then you already receive enough dietary BCAAs to fulfill all normal physiological functions. However, this in no way means you cannot derive added benefit from supplementing with BCAAs.

A 2009 study published in the “Journal of the International Society of Sports Nutrition” tested the effects of BCAA supplementation in comparison to whey protein supplementation or simple carbohydrates (from a sports drink) in athletes. All subjects consumed the same diet and participated in the same physical training regimen. At the end of the 8 week study, the BCAA group significantly outperformed both the whey group and carbohydrate group in terms of lean body mass as well as strength. Results like these make us question whether skeptics of BCAAs have even bothered to read the literature. There is more than enough evidence to conclude that BCAA supplementation can have a significant anabolic effect in both protein deficient AND non-protein deficient humans.

A major criticism of BCAA supplements is that Leucine alone can achieve a significant increase in muscle protein synthesis. While Leucine does appear to be the most critical in regards to muscle protein synthesis, a 2009 study published in the “Journal of the International Society of Sports Nutrition” concluded that BCAAs (2:1:1) have a more pronounced effect on protein synthesis than the same amount of Leucine alone. So, theoretically speaking, if you had to choose, you would choose Leucine, but all three is undeniably a better way to go.

We are concerned about the actual amount of BCAAs present in the Assault formula, which is likely negligible. Though we aren’t completely dismissing the enhanced absorption theory which forms the basis of combining BCAAs and Nitric Acid, even 100% absorption would hardly be sufficient given the present dose.


Choline, once inside the body, is converted into the neurotransmitter acetylcholine which is associated with many functions including (but not limited to) memory, attention, and muscle control. It is the neurotransmitter most closely associated with the “mind-muscle connection” (although this may be something of an over-simplification), and therefore of much interest to athletes and bodybuilders alike. While certain forms of choline may be associated with increased muscular power output (namely Alpha GPC), Choline Bitartrate is generally considered the least bioavailable choline source, though oral doses of 1000-2000mg have still been shown to increase serum choline levels significantly.

A 2012 study published in the “British Journal of Nutrition” found that 1 gram of Choline Bitartrate was able to significantly increase, not only plasma choline levels, but also plasma Betaine levels. Betaine itself is commonly included in pre-workout formulas as it has been shown, in some cases, to increase power output. While Choline Bitartrate has not been studies in regards to performance enhancement, it is just as effective at increasing Betaine as supplemental Betaine, meaning it may very well convey the same performance enhancement benefits.


Glucuronolactone has become a popular additive in energy drinks as well as “detox” supplements which claim cellular protective benefits. Despite being included in various energy products, it has not been studied in isolation in regards to any claims made by these companies. For now, we cannot say with any certainty whether Glucuronolactone makes any difference with regards to workout performance.


PurEnergy is a patent combination of Pterostilbene (a Resveratrol derivative) and Caffeine, alleged be superior to Caffeine in terms of absorption (slower) and half-life (longer). The only study was conducted by Chromadex, the company that manufactures PurEnergy, but the results do seem to back up the claims. Ultimately, PurEnergy may allow for more sustained energy than ordinary caffeine. We suspect PurEnergy will start to turn up in more and more energy supplements, and hopefully we will have some third-party studies to further validate (or diminish) the claims made by the manufacturer. For now, we’re on-board with the use of PurEnergy as a means of helping to prevent the usual “crash” associated with regular caffeine.


Huperzine A is an acetylcholinesterase inhibitor which means it blocks the enzyme that breaks down the neurotransmitter acetylcholine, resulting in increased levels of acetylcholine. Acetylcholine controls skeletal muscl and is largely responsible for the ‘mind-muscle connection’ that fitness experts often talk about. In addition to controlling the muscles, acetylcholine is also involved in learning, memory, decision making, and various other mental activities. Huperzine A, combined with the above mentioned Choline Bitartrate, may very well increase levels of acetylcholine to a significant and noticeable degree over time.


Contrary to popular belief, Taurine is not a stimulant but rather an an amino acid with anti-oxidant properties. In a 2011 study, Taurine was shown to significantly decrease oxidative stress in skeletal muscle following exercise. Prior to that, a 2004 study showed that Taurine may decrease exercise induced DNA damage, as well as “enhance the capacity of exercise due to its cellular protective properties”. A recent 2013 study noted a 1.7% improvement in 3k-time trial of runners after supplementing with Taurine, but noted that more research would be required to determine the exact mechanism of action.

It’s unfortunate that Taurine has developed a sort of stigma because of its inclusion in energy drinks. While Taurine does not provide “energy” in the way that caffeine does, several studies have shown its effectiveness as an antioxidant with workout-enhancing properties, and while the exact mechanism of action remains unknown, it appears likely that Taurine may improve exercise performance by reducing some of the cellular oxidative damage that generally leads to fatigue. The usual dose of Taurine used for performance enhancement is about 1 gram.


Coconut Water has become quite popular in the beverage (specifically sports drink) industry because of its natural electrolyte profile. Yes, electrolytes are incredibly important for proper inter-cellular communication, and the need for electrolytes may increase with prolonged exercise. However, it is unclear whether there is any benefit of the “natural” electrolytes found in Coconut Water beyond those conveyed through synthetic electrolyte supplementation. There is likely no difference, but Coconut Water does provide an all-in-one source of electrolytes so it shouldn’t be viewed as a negative either.


Glutamine is a non-essential amino acid (your body can make it) required for a wide range of bodily processes, from immune health to providing an alternative fuel-source for the brain. Because glutamine is an amino acid, some people assume that it may have a muscle sparing effect, but these claims are largely unsubstantiated. That being said, the benefits of Glutamine may instead pertain to fighting exercise induced immune system suppression. While it is true that our immune systems ultimately benefit from regular exercise, in the short-term, exercise actually temporarily lowers our immune system, thus making us more susceptible to infection during that time-frame. This temporary compromise of the immune system has been shown to correlate with lower levels of Glutamine. For this reason, it is suggested that increased uptake of glutamine may help keep the immune system strong post-exercise. In addition, lower glutamine levels have been recorded in over-trained athletes, suggesting that higher levels of glutamine may help to prevent overtraining.


In recent years, MusclePharm has strived to be at the forefront of supplement industry innovation. The use of new ingredients such as PurEnergy and CreNitrate certainly help to differentiate the Assault formula, but to say that it is superior to all other pre-workouts would be an exaggeration. There are some ingredients in Assault, such as DMG and Glucuronolactone, that are unsubstantiated by science, and likewise, some of the claims made by MusclePharm about the product are at least slightly exaggerated. However, the formula does contain a substantial amount of Nitrate in the form of various Nitrate containing compounds as well as a substantial dose of Beta-Alanine and Caffeine. So, while there are some aspects of the Assault formula we disagree with, ultimately it is an effective pre-workout supplement.

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