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Sports Supplement Product Review
By Anssi Manninen, MHS
MET-Rx Xtreme Amped Up Energy
Pre-workout Focus and Intensity Booster
Founded in 1991, MET-Rx Engineered Nutrition revolutionized the industry with a highprotein meal replacement product which actually tasted good. Over the years, MET-Rx meal
replacements have been used extensively by athletes and celebrities worldwide. Continuing a
commitment to well-designed products, MET-Rx recently introduced a new product line called
MET-Rx Xtreme.
In this article, I will discuss Xtreme Amped Up Energy, which is designed to amp up
both mental and physical energy levels before training:
Heat Inducer— thermogenic properties raise your body temperature to get you
ready to do battle in the gym or during competition.
Pre-workout Focus and Intensity Booster— to help you tear through the gym at a
blistering pace.
Fatty Acid Mobilizer— stimulates lipolysis to increase circulating fatty acid levels,
promoting fat utilization during training sessions.
The main actives of Xtreme Amped Up Energy are caffeine, green tea extract,
chocamine, tyrosine and vinpocetine. So, let’s examine some science behind these ingredients.
Caffeine
Caffeine is probably the most popular performance-enhancing substance known to
mankind. This can partly be attributed to its safety, wide availability and low price. A recent
study by Doherty and Smith at the University of Luton in the UK used the meta-analytic
approach (the process of synthesizing research results by using various statistical methods to
retrieve, select and combine results from previous separate, but related, studies) to examine the
effects of caffeine on athletic performance.
The authors limited their investigation to lab-based, double-blind, fully randomized,
placebo-controlled trials using adult subjects, published in peer-reviewed scientific journals. In
other words, only well-controlled studies were included. As expected, the results clearly indicate
that caffeine improves endurance performance and to lesser extent, high-intensity exercise.
More recently, the same investigators used the meta-analysis approach to examine the effects
of caffeine ingestion on ratings of perceived exertion. In comparison to fake supplementation
(placebo), caffeine reduced ratings of perceived exertion during exercise by 5.6 percent. Not
surprisingly, caffeine also improved exercise performance by 11.2 percent.
As caffeine is a mild diuretic, some have speculated that it may have adverse effects on
an athlete´s fluid balance. However, a comprehensive literature review, published in the
International Journal of Sports Nutrition and Exercise Metabolism, concluded, ”Athletes and
recreational enthusiasts will not incur detrimental fluid-electrolyte imbalances if they consume
[caffeine] in moderation.”
Green Tea
Green tea has thermogenic properties and promotes fat burning beyond that explained
by its caffeine content per se. A recent 12-week, double-blind study by Nagao and co-workers
investigated the effects of green tea extract on body fat reduction in healthy men. Interestingly,
the results revealed that bodyweight, waist circumference, body fat mass and subcutaneous fat
areas were significantly lower in the green tea extract group than in the control group.
Specifically, the green tea group lost about 1.4 kilograms of pure lard, while the control group
lost only 0.7 kilograms (1 kilogram equals 2.2 pounds). As expected, green tea treatment had
no adverse effects. In addition, there’s evidence that green tea can improve endurance
performance by increasing utilization of fatty acids as a source of energy in muscles during
exercise.
Chocamine
Chocamine is a proprietary cocoa extract containing numerous constituents. The
combination of these ingredients purportedly produce a unique effect. While scientific evidence
is limited, promotional literature suggests that chocamine increases athletic performance,
suppresses appetite, increases lipolysis, improves mood, increases alertness and so on. The
main actives of chocamine are likely methylxanthines (e.g., theobromine), biogenic amines
(e.g., tyramine) and certain amino acids (e.g., tryptophan).
Tyrosine
Tyrosine, a non-essential amino acid, is essential for the production of catecholamine
transmitters, including dopamine, noradrenaline and adrenaline. A review paper published in
1992 concluded that tyrosine may be useful in counteracting stress-related performance
decrement and mood deterioration by increasing depleted brain noradrenaline levels.
Vinpocetine
Vinpocetine is a synthetic ethyl ester of apovincamine, a vinca alkaloid obtained from
the leaves of the Lesser Periwinkle (Vinca minor). Promotional literature suggests that
vinpocetine supplementation can prove “incredibly efficacious” for athletes who need to be lean
and focused for competition. Vinpocetine increases blood circulation and metabolism in the
brain. In three studies of older adults with memory problems associated with poor brain
circulation or dementia-related disease, vinpocetine produced significantly more improvement
than a placebo in performance on tests reflecting attention, concentration and memory.
However, it’s unclear how vinpocetine affects healthy, young athletes.
Warning
Realize that Xtreme Amped Up Energy is a potent product, so read and follow all label
instructions prior to use. Consult with your physician or a licensed health care professional
before taking this product if you have a medical condition or if you’re taking any medication.
Xtreme Amped Up Energy contains a fair dose of caffeine, so limit use of caffeine-containing
medication, foods or beverages while taking this product. Too much caffeine may cause serious
adverse effects. Don’t use this product if you’re pregnant or nursing.
For more information on MET-Rx supplements, visit their website at www.metrx.com.
If you wish to get your product featured in ”Sports Supplement Product Review,” e-mail
Anssi Manninen; [email protected].
The author of this article has no financial relationship with MET-Rx.
References:
1. Doherty M, Smith PM. Effects of caffeine ingestion on exercise testing: a metaanalysis. Int J Sport Nutr Exerc Metab, 2004 Dec;14(6):626-46.
2. Doherty M, Smith PM. Effects of caffeine ingestion on rating of perceived exertion
during and after exercise: a meta-analysis. Scand J Med Sci Sports, 2005
Apr;15(2):69-78.
3. Armstrong LE. Caffeine, body fluid-electrolyte balance, and exercise performance.
Int J Sport Nutr Exerc Metab, 2002 Jun;12(2):189-206.
4. Nagao T et al. Ingestion of a tea rich in catechins leads to a reduction in body fat
and malondialdehyde-modified LDL in men. Am J Clin Nutr, 2005 Jan;81(1):122-9.
5. Murase T et al. Green tea extract improves running endurance in mice by
stimulating lipid utilization during exercise. Am J Physiol Regul Integr Comp
Physiol, 2006 Jun;290(6):R1550-6.
6. Tolson D. Chocamine description. http://www.1fast400.com/i62_Chocamine.html
7. Owasoyo JO et al. Tyrosine and its potential use as a countermeasure to
performance decrement in military sustained operations. Aviat Space Environ Med,
1992 May;63(5):364-9.
8. Clayton S. Vinpocetine. http://www.bodybuilding.com/fun/southfacts_vin.htm
9. McDaniel LA et al. Brain-specific" nutrients: a memory cure? Nutrition, 2003 NovDec;19(11-12):957-75.