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Xenadrine Core Pre-Workout Review

Xenadrine Core Pre-Workout is, as the name implies, a pre-workout by the makers of Xenadrine (MuscleTech/Iovate). It contains several well-known pre-workout ingredients like Beta-Alanine, Citrulline, and Glycerol, as well as some much lesser-known (and not extensively-researched) focus/energy ingredients…

Xenadrine Core Pre-Workout

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Beta-Alanine

Beta-Alanine is the rate limiting amino acid in the synthesis of the dipeptide, Carnosine, which acts as a lactic acid buffer in muscle tissue.  Reducing the build-up of lactic acid can directly enhance muscular endurance, and this has been demonstrated throughout multiple studies in both athletes and non-athletes alike.

A 2002 study from the “Japanese Journal of Physiology” which measured the Carnosine levels of sprinters found that individuals with higher muscular Carnosine levels exhibited higher power outputin the latter half of a 30m sprint (due to less lactic acid build-up).

Multiple studies have confirmed that Beta Alanine supplementation increases muscular Carnosine in a dose dependent manner. 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.

Xenadrine Core Pre-Workout contains the standard 1600mg per serving dose found in many other pre-workouts.

L-Citrulline

Citrulline is an amino acid which serves as a precursor to Arginine, and therefore is directly involved in the production of Nitric Oxide.  Unlike supplemental Arginine, however, Citrulline is quite reliable at increasing plasma Arginine and ultimately enhancing performance.

Citrulline has been shown to increase muscular contraction efficiency, meaning less ATP is required for a given workload.  This mechanism explains why subjects who consumed Citrulline were able to perform more reps later on in the workout compared to subjects who consumed a placebo.  Additionally, Citrulline has been shown to reduce muscle soreness effectively making it both a performance enhancing ingredient as well a recovery agent.

Unfortunately, the 1500mg dose present in Xenadrine Core Pre-Workout is less than what has been used clinically, though two servings may yield an effective dose.

Glycerol

Glycerol has become pretty popular over last couple years as a pump-inducing ingredient in pre-workout supplements. It’s mechanism of action is simple: Glycerol draws water into cells which can directly enhance what we all know as “The Pump”. Beyond that, Glycerol has been alleged to have actual performance enhancement implications as well.

A 1996 study, published in the “International Journal of Sports Medicine”, found that Glycerol supplementation prior to exercise increased endurance in cyclists. These findings were replicated in a 1999 study from the “European Journal of Applied Physiology and Occupational Physiology” in which pre-exercise Glycerol supplementation enhanced time performance (also in cyclists).

A 2003 study, published in the “Medicine and Science in Sports and Exercise”, found that, while post-exercise Glycerol supplementation prevented exercise-induced dehydration, this had no impact on performance measures (compared to placebo).

The research as a whole indicates that Glycerol can be an effective pump agent (due to water retention), but may only noticeably enhance performance (endurance not strength) during long-duration exercise when dehydration becomes a contributing factor to fatigue.

Xenadrine Core Pre-Workout contains HydroMax Glycerol which yields more actual Glycerol than other forms such as Glycerol Monostearate, so 500mg way actually be an effective dose.

Caffeine Anhydrous

Caffeine triggers the release of Catcholamines (Noradrenaline, Dopamine, Adrenaline, etc.), generally inducing a state of alertness and increased focus.

Caffeine also directly enhances calcium-ion release in muscle tissue, which directly increases muscle contraction force. Rather than discuss dozens of studies, we’ll leave it at this: Caffeine is an effective performance enhancer (and mental stimulator), but a tolerance is generally built-up with continuous use.

Xenadrine Core Pre-Workout contains 180mg of Caffeine per serving, a moderately effective dose for the average non-habitual Caffeine user.

Yerba Mate

Yerba Mate contains Xanthines such as Caffeine and Theobromine.  Although some of these compounds may have their own distinct benefits, in the context of XenCore Hardcore Pre Workout, we’d consider Yerba Mate just another source of Caffeine.  How much?  We don’t know.

Mucuna Pruriens

Mucuna Pruriens contains L-Dopa, a direct precursor to the neurotransmitter Dopamine.  Although Mucuna Pruriens (assuming the right dose) may effective increase Dopamine levels in the brain, it remains unclear how this might impact exercise performance.  Certainly there are mechanisms by which Mucuna Pruriens could favorably impact exercise performance but without any studies on the topic, it’s tough to say for sure.

Mucuna Pruriens was popular in early pre-workouts (such as C4 Extreme) but has since been phased out (one would think because it’s not that great), though it seems like MuscleTech hasn’t given up on it.  In the context of Xenadrine Core Pre-Workout, we wouldn’t consider it a particularly vital ingredient.

Salvia Officinalis:

MuscleTech has used Salvia Officinalis before in such products as Hydroxycut SX-7, though it isn’t quite clear how it fits into a pre-workout supplement.

Theanine

With the overwhelming amount of evidence indicating that Theanine enhances the positive effects of Caffeine AND reduces the negative effects, it amazes us that more brands don’t use it. Theanine and Caffeine is one of the few combinations that can actually be considered synergistic, rather than merely additive.

Theanine is effective in doses of 50-200mg and the synergistic benefits depend on how much Caffeine is being consumed with it.  Xenadrine (MuscleTech) doesn’t disclose the amount of Theanine present in Core Pre-Workout, but we’d estimate around 50mg or so.

Perilla Frutescens

Perilla Frutescens is generally standardized for Rosmarinic Acid (also found in Rosemary) which has some general health implications which can mostly be attributed to its antioxidant properties.  So far, we have only come across this ingredient in Xenadrine Core where we also didn’t really understand what it was supposed to do.

Centella Astiatica

Centella asiatica, more commonly known as Gotu Kola, is an Ayurvedic herb which has traditionally been used as a cognitive enhancement agent. A 2005 study, published in “Physiology and Behavior”, found that mice given 200mg/kg of Gotu Kola extract daily for 15 days were able to better navigate in a series of maze test (enhanced memory). These results were replicated in a 2007 study from “Neurosciences”.

Like some of the previous ingredients, Gotu Kola can also be found in Xenadrine Core where MuscleTech alleges that it supports the “sensory experience”, and preliminary evidence suggests this may be true.

The Bottom Line

Xenadrine Core Pre-Workout contains the usual array of performance enhancing ingredients such as Beta-Alanine, Citrulline, etc. as well as some much more speculative ingredients meant to enhance focus/energy.  In this regard it is similar to Xenadrine Core (since it uses some of the same ingredients), but some of the more established ingredients are a little under-dosed.

Still don’t know which pre-workout is right for you? Check out our Top 10 Pre-Workout Supplements List!

REFERENCES
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