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The Ultimate Pre-Workout Stack

Brian Turner

Posted on June 01 2016

The ultimate stack is the perfect union of ingredients that seamlessly complement each other in many ways, ultimately generating superior muscular performance. Advanced Molecular Labs (AML) has created the ultimate pre-workout stack with the release of its new product, AML Power Rep™. When stacked with its recently released AML Preworkout, AML Power Rep™ provides the ultimate in pre-workout supplementation. This powerful combination will load your muscles with energy and vastly improve muscular strength and endurance, so you can push your body to new limits for longer periods of time— and revitalize a sluggish central nervous system (CNS) for greater motivation to get into the gym and start pounding the weights with extreme intensity and resilience!

The optimal timing for this stack would be to drink AML Preworkout one hour before entering the gym, giving enough time for the supplement to boost energy and motivation. Then, right before you start training, take the recommended dosage of AML Power Rep™ for an additional boost that will provide endless energy, mental focus and strength for the entire workout.


Caffeine is a solid foundation for any pre-workout supplementation protocol. That is because caffeine triggers a number of mechanisms that enhance exercise performance, including greater muscular contraction force, increased cellular energy production within muscle tissue and stimulation of the CNS. While increased contractile forces and energy production within muscle from caffeine can improve muscular strength and endurance, caffeine’s ability to stimulate the CNS improves exercise performance in multiple ways. Caffeine activates the CNS by directly inhibiting the adenosine receptor in the brain, triggering the release of two neurotransmitters, dopamine and adrenaline.1 This surge of dopamine and adrenaline amps-up the neurochemical environment within the brain, reducing fatigue and sluggishness for greater concentration and intensity while training in the gym.2 The surge of neurotransmitters also improves overall energy and mood3, making it an ideal pre-workout supplement and a key ingredient in AML Preworkout.

Although caffeine is a remarkable performance-enhancing supplement that should be part of any serious pre-workout supplement, stacking it with theacrine and p-synephrine, two compounds found in AML Power Rep™, will heighten some of the impressive ergogenic effects of caffeine, based on their independent ability to improve energy production and reduce fatigue. Theacrine is a protoalkaloid, with a similar chemical structure to caffeine, and it triggers dopamine release in a similar fashion to caffeine, improving arousal and motivation. This effect was shown in an initial study where theacrine increased energy, diminished fatigue and improved concentration, just like caffeine.4 However, unlike caffeine, which can produce a tolerance after as little as four days of consumption5, theacrine use for up to seven days showed no signs of desensitization.

The research indicates that the combined intake of caffeine with theacrine should enhance mood and energy, with no decrease in potency, for longer periods of time— effectively increasing overall arousal and focus before hitting the gym.5 Furthermore, the combined use of caffeine and theacrine plausibly stimulates the release of greater levels of dopamine, as a second study by Kuhman et al.6 showed that combining theacrine with caffeine had a greater impact on feelings of energy and mood relative to the consumption of caffeine alone, demonstrating an additive effect from consuming both caffeine and theacrine.

AML Preworkout is also loaded with tyrosine and the tropical plant Mucuna pruriens, which contains the dopamine precursor L-dopa.7 Together, both of these ingredients effectively increase dopamine production as well8,9, meaning their combined intake with caffeine and theacrine in this potent pre-workout stack will foster even greater focus and concentration while training.

Stacking caffeine with the second protoalkaloid in AML Power Rep™, p-synephrine, will give rise to even greater energy levels within the muscle cell, delivering superior muscular endurance, as p-synephrine also converts glucose and fat into energy10 for the muscle cell, just like caffeine. The apparent improvement in muscular energy levels was demonstrated in a study by Ratamess et al.11, which found that taking 100 milligrams of p-synephrine (the same amount in AML Power Rep™ ) right before you start training improved performance, increasing the total amount of repetitions completed during the study— demonstrating improved muscle endurance.


Another performance-enhancing effect from stacking AML Preworkout with AML Power Rep™ will be an extraordinary capacity to reduce the pain associated with weight training. The capacity to blunt pain tends to reduce perceived exertion during exercise, increasing the capacity to train with higher levels of intensity for longer periods of time, ultimately increasing the training effect. This analgesic effect will come from three of the ingredients in this stack: ATP, caffeine and theacrine.

The pain-reducing effect from all three compounds is triggered when each binds to a specific set of purine receptors embedded within the cell membrane of certain spinal cord and peripheral neurons. The interaction with the purine receptor initiates certain cellular-signaling cascades within these neurons, mitigating pain sensitivity. This ability to minimize pain likely contributes to the lower rating of perceived exertion (RPE) reported by test subjects after consuming caffeine. In a recent review of 21 independent studies investigating the influence of caffeine on RPE, it was found that caffeine reduced RPE during exercise by 5.6 percent.12 In addition, this review also showed that caffeine improved exercise performance by 11.2 percent, suggesting that the lowered RPE during exercise from caffeine use likely represents one of the performance-enhancing mechanisms triggered by caffeine. Theacrine also exerts an analgesic effect. One study showed that oral consumption of theacrine in mice reduced pain perception from a hot plate, and pain associated with the injection of the compound acetic acid.13

The ability of caffeine to reduce pain perception during exercise, and enhance muscular performance, implies that ATP and theacrine can do the same. Thus far, there are no studies linking either ATP or theacrine intake to reduced RPE, despite their obvious pain-reducing effects. However, it is reasonable to propose that ATP and theacrine can minimize RPE during training, and enhance exercise performance. In fact, the muscle-enhancing effects demonstrated in the study by Wilson et al.14, where 12 weeks of ATP supplementation (400 milligrams of ATP from Peak ATPÆ before your workout, the same amount found in AML Power Rep™!) increased total-body strength, are likely produced to some degree by the analgesic effect of ATP— as greater muscular contraction force can be stimulated by the removal of pain sensation. Taken together, these studies indicate that stacking caffeine, ATP and theacrine will provide a heightened analgesic effect, allowing for exceptional training intensity and immediate strength gains.


Another indispensable capacity of pre-workout supplementation is the ability to improve muscular endurance. Stacking AML Preworkout with AML Power Rep™ will reduce muscular fatigue and improve muscular endurance tremendously! Not only will this reduce the rate of perceived exertion, allowing for more intense training, as previously mentioned— but this much ATP will boost nitric oxide and prostacyclin and  improve muscular endurance by potently stimulating vasodilation. ATP is stored in red blood cells. When oxygen is low in the working muscle, the red blood cell releases ATP, resulting in vasodilation and greater blood flow (up to 59%) to the working muscle groups that enhances nutrient and oxygen delivery15,16, resulting in greater muscular endurance.

In addition to the greater blood flow triggered by the dose of ATP within this stack, AML Preworkout also contains the potent nitric oxide-boosting compound citrulline malate, along with watermelon and grape skin extracts, which contain polyphenol antioxidant compounds that powerfully stimulate nitric oxide production17 and potently induce vasodilation, meaning increased levels of vasodilation that further improve muscular endurance.


AML Preworkout is also loaded with several other compounds that will improve exercise performance. Within muscle cells, beta-alanine functions as a key building block for carnosine, the primary buffer within muscle tissue that counters the negative impact of lactic acid on exercise capacity. Several independent studies have clearly illustrated the positive influence of beta-alanine on carnosine production in muscle. In these studies, a significant increase in muscle carnosine of approximately 40 to 50 percent was measured after beta-alanine ingestion over a four- to eight-week time frame.18, 19 In addition to beta-alanine supporting carnosine synthesis, beta-alanine intake has also been shown to reduce muscle acidosis. In one study, subjects consuming beta-alanine for four weeks showed a much slower rise in acidity during high-intensity exercise.20 Moreover, the muscle-buffering function associated with beta-alanine intake has also been shown to improve endurance, as illustrated in a study where subjects ingesting beta-alanine demonstrated major improvements while performing a medium-intensity, high-repetition squat workout, compared to a placebo group.21


The final element of the ultimate pre-workout stack is the capacity to increase muscular size and strength. AML Preworkout is loaded with creatine monohydrate and natural betaine (from BetaPower™), which stimulates greater production of creatine for a remarkably effective muscle-building effect. Creatine monohydrate is one of the most heavily used supplements22, packing on substantial muscle size and strength. Many studies over the years have demonstrably shown that short-term creatine monohydrate supplementation increases strength output during intense exercise. Furthermore, creatine supplementation with heavy weight training has the potential to stimulate muscle hypertrophy.23 In addition, AML Preworkout contains betaine, which supplies a methyl group required for the biosynthesis of the muscle-building creatine molecule.24 Supporting this function, it has been shown that betaine ingestion significantly increases anaerobic power in the bench press and squat. Interestingly, additional studies have also shown that betaine increased muscle protein synthesis and lean body mass while also reducing abdominal fat25, 26, likely because of its impact on creatine biosynthesis.

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For most of Michael Rudolph’s career he has been engrossed in the exercise world as either an athlete (he played college football at Hofstra University), personal trainer or as a research scientist (he earned a B.Sc. in Exercise Science at Hofstra University and a Ph.D. in Biochemistry and Molecular Biology from Stony Brook University). After earning his Ph.D., Michael investigated the molecular biology of exercise as a fellow at Harvard Medical School and Columbia University for over eight years. That research contributed seminally to understanding the function of the incredibly important cellular energy sensor AMPK— leading to numerous publications in peer-reviewed journals including the journal Nature. Michael is currently a scientist working at the New York Structural Biology Center doing contract work for the Department of Defense on a project involving national security.


1. Zheng X, Takatsu S, et al. Acute intraperitoneal injection of caffeine improves endurance exercise performance in association with increasing brain dopamine release during exercise. Pharmacol Biochem Behav 2014;122, 136-143.
2. Einother SJ and Giesbrecht T. Caffeine as an attention enhancer: reviewing existing assumptions. Psychopharmacology (Berl) 2013;225, 251-274.
3. Nehlig A. Is caffeine a cognitive enhancer? J Alzheimers Dis 2010;20 Suppl 1, S85-94.
4. Habowski SM, Sandrock J, et al. The effects of Teacrine, a nature-identical purine alkaloid, on subjective measures of cognitive function, psychometric and hemodynamic indices in healthy humans. Int J Med Sci 2014;11.
5. Ball KT and Poplawsky A. Low-dose oral caffeine induces a specific form of behavioral sensitization in rats. Pharmacol Rep 2011;63, 1560-1563.
6. Kuhman DJ, Joyner KJ and Bloomer RJ. Cognitive Performance and Mood Following Ingestion of a Theacrine-Containing Dietary Supplement, Caffeine, or Placebo by Young Men and Women. Nutrients 2015;7, 9618-9632.
7. Alleman RJ Jr, Canale RE, et al. A blend of chlorophytum borivilianum and velvet bean increases serum growth hormone in exercise-trained men. Nutr Metab Insights 2011;4, 55-63.
8. Tumilty L, Davison G, et al. Oral tyrosine supplementation improves exercise capacity in the heat. Eur J Appl Physiol 2011;111, 2941-2950.
9. Tharakan B, Dhanasekaran M, et al. Anti-Parkinson botanical Mucuna pruriens prevents levodopa induced plasmid and genomic DNA damage. Phytother Res 2007;21, 1124-1126.
10. Hong NY, Cui ZG, et al. p-Synephrine stimulates glucose consumption via AMPK in L6 skeletal muscle cells. Biochem Biophys Res Commun 2012;418, 720-724.
11. Ratamess NA, Bush JA, et al. The effects of supplementation with P-Synephrine alone and in combination with caffeine on resistance exercise performance. J Int Soc Sports Nutr 2015;12, 35.
12. Doherty M and Smith PM. Effects of caffeine ingestion on rating of perceived exertion during and after exercise: a meta-analysis. Scand J Med Sci Sports 2005;15, 69-78.
13. Wang Y, Yang X, et al. Theacrine, a purine alkaloid with anti-inflammatory and analgesic activities. Fitoterapia 2010;81, 627-631.
14. Wilson JM, Joy JM, et al. Effects of oral adenosine-5’-triphosphate supplementation on athletic performance, skeletal muscle hypertrophy and recovery in resistance-trained men. Nutr Metab (Lond) 2013;10, 57.
15. Sprague RS, Bowles EA, et al. Erythrocytes as controllers of perfusion distribution in the microvasculature of skeletal muscle. Acta Physiol (Oxf) 2011;202, 285-292.
16. Trautmann A. Extracellular ATP in the immune system: more than just a ìdanger signal.î Sci Signal 2009;2, pe6.
17. Resende AC, Emiliano AF, et al. Grape skin extract protects against programmed changes in the adult rat offspring caused by maternal high-fat diet during lactation. J Nutr Biochem 2014;24, 2119-2126.
18. Harris RC, Tallon MJ, et al. The absorption of orally supplied beta-alanine and its effect on muscle carnosine synthesis in human vastus lateralis. Amino Acids 2006;30, 279-289.
19. Stellingwerff T, Anwander H, et al. Effect of two beta-alanine dosing protocols on muscle carnosine synthesis and washout. Amino Acids 2010;42, 2461-2472.
20. Baguet A, Koppo K, et al. Beta-alanine supplementation reduces acidosis but not oxygen uptake response during high-intensity cycling exercise. Eur J Appl Physiol 2010;108, 495-503.
21. Hoffman J, Ratamess NA, et al. Beta-alanine and the hormonal response to exercise. Int J Sports Med 2008;29, 952-958.
22. Buford TW, Kreider RB, et al. International Society of Sports Nutrition position stand: creatine supplementation and exercise. J Int Soc Sports Nutr 2007;4, 6.
23. Harris RC, Soderlund K and Hultman E. Elevation of creatine in resting and exercised muscle of normal subjects by creatine supplementation. Clin Sci (Lond) 1992;83, 367-374.
24. Byerrum RU, Sato CS and Ball CD. Utilization of Betaine as a Methyl Group Donor in Tobacco. Plant Physiol 1956;31, 374-377.
25. Brigotti M, Petronini PG, et al. Effects of osmolarity, ions and compatible osmolytes on cell-free protein synthesis. Biochem J 2003;369, 369-374.
26. Hoffman JR, Ratamess NA, et al. Effect of 15 days of betaine ingestion on concentric and eccentric force outputs during isokinetic exercise. J Strength Cond Res 2011;25, 2235-2241