Muscle Insider
New member
Maximize your exercise performance without the caffeine crash or jittery brain-drain.
When it comes to stimulants and the best pre workout supplements, there’s really no contest: everyone loves caffeine.
Sure, in our Adderall age, there are certainly more powerful stimulants available. However, for a more sustainable headrush with a limited risk of long-term issues, caffeine remains a reasonable choice for boosting performance, both mentally and physically, and caffeine free pre-workouts are great for this.
Because caffeine is associated with “feel good” performance enhancement, many pre-workout supplements offer generous amounts of caffeine in their formulas, as well as really great vitamins and minerals. However, many of these same supplements tend to mask their poor-quality ingredient forms and overall ineffectiveness with caffeine megadoses, making these failed supplements for those looking for a good caffeine free pre workout supplement.
A few common problems with these cheap, weak supplements include:
Jitters related to excess stimulation
Poor absorption due to excess caffeine
Low-grade creatine forms linked to gastric distress
Unhealthy, pointless synthetic flavors and artificial additives
And more. In other words, caffeine isn’t the only problem with today’s standard pre-workout formula; although, it does often distinguish effective caffeine free pre-workout stacks from ineffective formulas.
As a reliable “dopaminergic” brain booster, caffeine can be used to trick consumers into thinking an inferior, cheap pre-workout supplement is working as they misattribute the noticeable “feel good” feelings of caffeine to the formula’s efficacy.
In this guide, we cover the advantages of avoiding caffeine in your pre-workout stack, as well as how you can optimize yours with the best stim-free ingredients.
But before diving into all of that, here is a deep-dive analysis of Transparent Labs PreSeries Stim-Free Pre-Workout, the best all-in-one caffeine free pre workout.
Best Pre-Workout Without Caffeine: Transparent Labs PreSeries Stim-Free Pre-Workout
Transparent Labs Stim-Free Pre-Workout is a 100% transparent formula great for serious athletes and bodybuilders looking for a high-intensity workout experience without caffeine.
Working with key ingredients like citrulline malate, beta-alanine, taurine, and others, this is a great supplement for those intolerant or avoiding caffeine. With clinically-effective dosages, this is a safe supplement to provide for a host of benefits.
Altogether, Transparent Labs Stim-Free Pre-Workout works by:
Increasing nitric oxide to the muscles to support enhanced muscular blood flow and oxygenation, priming the “muscle pump” feel for every great workout.
Enhancing focus to give raise alertness so you stay engaged throughout the entire workout.
Boosting endurance by working as a buffer for lactic acid build up and giving you a great endurance boost.
Promoting lean muscle growth for increased strength and definition for better training, performance, and that desired aesthetic.
Plus, with a transparent label and safe, effective ingredients, you know exactly what you are putting into your body.
Code GENIRON10 For 10% Off
Transparent Labs PreSeries Stim-Free is an amazing option for those looking for stimulant free supplements for strength training, weight loss, and improved performance. With key ingredients at effective dosages, this is a great pre-workout for anyone looking for stim-free options.
Formula Analysis
Citrulline Malate 2:1, 6,000mg
BCAA 2:1:1, 4,000mg
Beta-Alanine, 4,000mg
BetaPure Betaine Anhydrous, 2,500mg
Taurine, 1,300mg
L-Tyrosine, 1,000mg
Choline Bitartrate, 500mg
ElevATP Ancient Peat and Apple Fruit Extract, 150mg
BioPerine, 5mg
Huperzine A, 50mcg
Transparent Labs Stim-Free brings strength and endurance gains to a whole new level with a unique combination of highly potent, bioavailable, and caffeine-free pre-workout ingredients.
Compared to the standard hyper-caffeinated pre-workout supplements lining the shelves, this is a smarter, cleaner stack that provides a natural boost with all-natural, stim-free ingredients.
Plus, you don’t get those unwanted jitters or caffeine related side effects that typically ruin a great product. With no stimulants and a transparent label, this supplement also contains no artificial sweeteners, coloring, or preservatives and is gluten-free and non-GMO to truly maximize your athletic fitness and workout performance.
Shop Transparent Labs PreSeries Stim-Free Pre-Workout Here
[embedded content]
Stack with Transparent Labs StrengthSeries Creatine HMB and CoreSeries Post-Workout
To maintain consistent progress with your anabolic gains, fat loss, and other fitness-related goals, stacking a caffeine free pre workout supplement with a post-workout supplement and a “rest day” stack can help. A more complete Transparent Labs stack would look like:
Stim-Free Pre-Workout– a caffeine-free pre-workout enhancer designed to boost nitric oxide, muscle strength, and endurance.
Post– a post-workout formula designed to promote anabolic muscle gains and protect against muscle breakdown.
Creatine HMB– a creatine supplement perfect for restoring depleted muscle tissue and increasing strength.
Transparent Labs CoreSeries Post-Workout
Formula Analysis
L-Glutamine, 5,000mg
Betaine Anhydrous, 2,500mg
L-Carnitine L-Tartrate, 2,000mg
Beta-Alanine, 2,000mg
Tart Cherry Powder, 500mg
Astragin, 25mg
Transparent Labs Post is a great post-workout supplement to maximize muscle growth and see results immediately. Working to optimize recovery and muscle repair, the body needs targeted nutrients to fully recharge that are backed by science. With Post, you get great ingredients working together for the best results.
Altogether, the benefits of Post include:
Bolster nitric oxide production
Reduce delayed-onset muscle soreness
Facilitate protein synthesis
Enhance insulin sensitivity
Prime your body for growth and recovery
Code GENIRON10 For 10% Off
Transparent Labs CoreSeries Post is a great supplement to optimize recovery and muscle repair with 6 great ingredients. Paired well with any protein supplement, this can ensure big gains are met.
Transparent Labs StrengthSeries Creatine HMB
Formula Analysis
Creapure Creatine Monohydrate, 5,000mg
B-Hydroxy B-Methylbutyrate (HMB), 1,500mg
BioPerine Black Pepper Extract, 5mg
Transparent Labs Creatine HMB will work to boost performance without losing those hard-earned gains. The added ingredient of HMB along with creatine works in tandem to promote growth, recovery, and provide for the best results possible. BioPerine is exactly what you need to increase absorption so nothing goes to waste.
Altogether, the benefits of Creatine HMB include:
Promote strength and lean muscle
Increase endurance
Prevent lean muscle loss
Decrease fat mass
Code GENIRON10 For 10% Off
Transparent Labs Creatine HMB is clean and effective for tackling all of your strength building needs. With no artificial additives or preservatives, what you get is pure creatine with added HMB for better strength.
The World’s Favorite Drug: Caffeine
Coffee, tea, soda, energy drinks, energy shots, pre workout supplements, fat loss supplements, nootropic supplements, energy-boosting gum pack—more and more, it seems like caffeine is sneaking its way into everything these days. And from a seller’s point of view, this makes sense: caffeine makes people feel great, and people buy things that make them feel good (1).
What’s more, caffeine makes people feel good in a reliable way that’s relatively safe to other habit-forming stimulants and quote-unquote “drugs.”
As a naturally occurring compound, caffeine is found in roughly sixty different plant species, including (2):
Coffee Beans
Tea Leaves
Cocoa Beans
Kola Nuts
Yerba Maté
Guarana Berries
Guayusa
Yaupon Holly
Which is interesting and all, but the more important question here is:
What Exactly Is Caffeine?
Caffeine, or 1,3,7-trimethylxanthine (if you want to get fancy with it), is an alkaloid, which means that its chemical structure is predominated by nitrogen. Pure caffeine is highly water-soluble and can, thus, act rapidly on the brain and body after ingestion without aid of fatty foods (as is the case with fat-soluble compounds) (3). Those sensitive to this strong stimulant would require a caffeine free pre workout for muscle building and lean muscle.
Structurally, caffeine is similar to adenosine, a compound that binds with adenosine receptors to induce cognitive drowsiness and fatigue. Which gives us the perfect segue into the more important question:
What Exactly Does Caffeine Do?
Caffeine, as a compound structurally similar to adenosine, binds to adenosine receptors to block the drowsiness of adenosine. In other words, caffeine achieves its stimulatory properties on the central nervous system (CNS) through its inhibitory effects on adenosine, resulting in a boost on:
Catecholamines – dopamine, norepinephrine, epinephrine, etc. (4).
Adrenal Activity– encouraging the release of stress hormone cortisol (5).
Dopamine Signaling – in high dosages (300+ mg), caffeine may increase the availability of dopamine receptors (6).
The Pros Vs. Cons Of Caffeine For Exercise
Several factors largely determine the advantageous vs. disadvantageous use of caffeine or caffeine free pre workout supplements for the best performance enhancement. However, perhaps the two most important factors are:
Dosage – the amount of caffeine per serving
Timing– when you take caffeine (i.e., morning or night?)
Caffeine Sensitivity– your personal tolerance to stimulants
Some people are more sensitive to caffeine than others, and therefore they require smaller dosages to reach peak effect. Others may feel like they need to guzzle a significant amount of caffeine just to reach their cognitive baseline so knowing the pros and cons is huge.
Pro #1 – Cognitive Performance
As a dopaminergic stimulant, caffeine may heighten mood and intensity for greater mental motivation in the gym. Taken prior to exercise, caffeine may help ward off mental fatigue in service of a more alert, more ready mindset.
Study: in a placebo-controlled study on caffeine consumption on judo athletes, morning caffeine ingestion was suggested to have “ergogenic properties with the potential to benefit performance, increase anxiety and vigor, and decrease the simple reaction time” (7).
Con #1 – Anxiety, Nervousness, and Jitteriness
Conversely, the mood- and intensity-boosting advantages of caffeine may also tip over into cognitive impairment by promoting anxiety, nervousness, and jitteriness, which is where a great caffeine free pre-workout would come in handy. Encouraging mental arousal, caffeine may often encourage too much arousal, throwing the mind into a scatterbrained state of anxiety that can be detrimental to athletic performance that requires cool composure.
Study: under conditions of anxiety disorder, caffeine consumption may exacerbate anxiety symptoms, potentially as a consequence of increased sensitivity to caffeine associated with anxiety disorder (8). Abstaining from caffeine altogether may significantly help maintain a level head under such conditions.
Pro #2 – Thermogenic Fat Loss
In addition to boosting cognitive arousal, caffeine’s stimulatory effects also seem to boost thermogenesis, or fat burning. By encouraging the activity of “fight or flight” catecholamines and stress hormones, caffeine seems to heighten the body’s energy expenditure capacity, potentially resulting in greater fat loss results during workouts.
Study: in one double-blind, placebo-controlled study, 100, 200, and 400 mg caffeine dosages were observed to determine what happened with thermogenic, metabolic, and cardio health measures. The results: caffeine dose-dependently increased thermogenic energy expenditure in association with increased plasma lactate and triglyceride levels (9).
Con #2 – Poor Sleep Quality
Nothing disrupts performance, endurance, and metabolic health quite like sleep deprivation. Contributing to a wide range of metabolic disorders and performance decrements, poor sleep quality is often associated with excess caffeine use and you won’t necessarily feel these effects with a caffeine free pre workout. And the relationship between the two is a downward spiral: caffeine promotes sleep deprivation, which encourages further caffeine use, and so on.
Study: comparing the sleep disruptive effects of caffeine administered at 0, 3, and 6 hours prior to bedtime, a group of researchers observed that “caffeine taken 6 hours before bedtime has important disruptive properties on sleep and provides empirical support for sleep hygiene recommendations to refrain from substantial caffeine use for a minimum of 6 hours prior to bedtime” (10).
Pro #3 – Vasoconstriction
Caffeine has a vasoconstrictive effect, meaning that this stimulant promotes the constriction of blood vessels, thereby decreasing blood flow. While this sounds like a negative (as we’ll get into in “Con #3” below), caffeine’s vasoconstriction may potentially have a pain-relieving effect on headaches, namely headaches associated with excessive flow to the brain.
Study: as one study on caffeine’s vascular mechanisms of action suggests, “caffeine has some cardiovascular properties and effects which could be considered beneficial,” (11) involving the association between decreased cerebral circulation and migrainous headache.
Con #3 – Vasoconstriction
One of the main reasons we take pre-workout supplements: boost circulation. And so, naturally, the vasoconstriction of caffeine are typically viewed as a negative when it comes to performance enhancement. Whether we’re talking nootropic cognitive enhancers or bodybuilder pre-workout stacks, the goal is to boost blood flow, not inhibit it and caffeine free pre workouts are great for this.
Study: in one 2009 study on the effects of daily caffeine use on cerebral blood flow, caffeine was shown to reduce cerebral blood flow by an average 27%, (12) which may significantly impact cognition and goes against the vasodilatory aims of pre-workout N.O. boosters.
Okay, So Is Caffeine A Legitimate Performance Enhancer?
Based on the study’s compiled above, the best performance enhancement potential of caffeine significantly depends upon how much caffeine you use, your personal caffeine tolerance, and when you take caffeine (i.e., how close to bedtime) so if sensitive, a caffeine free pre workout would be the way to go.
Of course, much of this is common sense.
But with a better understanding of how caffeine affects your mental and physical performance, you may make a smarter decision as to whether or not you want a caffeine free pre-workout supplement (or any stack for that matter).
An Optional Source Of Pre-Workout Caffeine: Transparent Labs PreSeries BULK Pre-Workout
Code GENIRON10 For 10% Off
Transparent Labs PreSeries BULK is backed by science with clinically effective dosages to increase muscle size and mass. This pre-workout is perfect for reducing fatigue, aiding in muscle growth, and boosting energy levels for better overall performance.
Transparent Labs BULK is the best bulking pre-workout for those looking to gain size and increase muscle mass. With 19 active ingredients and a transparent label, this supplement contains zero artificial sweeteners, flavors, or other additives for only the best in terms of your training and performance.
Top 5 Non-Caffeinated Pre-Workout Ingredients
Whether you’re looking at a caffeinated or caffeine free pre-workout supplement, some of the best pre-workout ingredients you need to look for include:
#1) Creatine
An organic compound highly concentrated in tissue, creatine works as precursor fuel for the natural production of ATP energy, a cleaner, more natural energy source than the stimulatory effects of caffeine. As a dietary supplement, it boosts exercise performance by (13,14):
Replenishing exercise-depleted ATP energy
Stimulating insulin-like growth factor 1 (IGF-1)
Buffering muscular lactic acid build-up for better endurance
Because creatine concentrates in muscle tissue, ongoing supplementation is required for creatine to reach peak saturation and, thus, peak ergogenic effect.
Best Pre-Workout Creatine: Creapure® pH10
Creapure® pH10 is 99.5% pure creatine monohydrate
pH-balanced to enhance bioavailability
Clean and easy-to-absorb to reduce bloating and gastric distress
#2) Beta-Alanine
A well-known sports nutrition aid, namely for the skin-tingling sensation associated with it, Beta-Alanine replenishes levels of carnosine, a dipeptide molecule, in muscle tissue, namely fast-twitch fibers for increased strength and power during high-intensity exercise. Consistently loading and maintaining, carnosine benefits performance and recuperation by (15):
Delaying onset fatigue and failure
Enhancing overall strength and stamina
Neutralizing exercise-induced free radicals
Inhibiting advanced glycation end-products (AGEs)
Buffering the impact of damaging acids
And more. The strength and endurance benefits of beta-alanine are unmatched and pair incredibly well with the endurance-boosting advantages of creatine supplementation and caffeine free pre workout.
Best Pre-Workout Beta-Alanine: CarnoSyn®
CarnoSyn® is the only beta-alanine with NDI (New Dietary Ingredient) status
Generally Recognized as Safe (GRAS)
Well-backed by years of clinical research
#3) L-Citrulline + L-Glutathione
L-Citrulline is an amino acid that, once absorbed, converts in the body to L-arginine, a nitric oxide (N.O.) booster that enhances muscular circulation, strength, and growth. In other words, L-citrulline works as your go-to pre-workout “muscle pump” booster and will help with mind-muscle connection.
Additionally, L-Glutathione is an antioxidant enzyme that, when paired with L-citrulline, benefits performance in a few ways. Combined, L-citrulline + L-glutathione work by (16):
Promoting oxygen delivery to tissue
Protecting muscle against oxidative stress
Sustaining L-citrulline’s N.O.-boosting bioactivities
Improving energy and anabolism
Strengthening immunity against gym-related challenges
And more. Stacking these two compounds may significantly boost performance and protect against the deleterious side effects of boosted performance.
Best Pre-Workout L-Citrulline + L-Glutathione: Setria® Performance Blend
Setria® Performance Blend is made by Kyowa Hakko Bio Co. Ltd., a world leader in supplement development
Kyowa Quality® L-Citrulline is exceptionally clean and bioavailable
Setria® is an advanced glutathione form that pairs well with Kyowa Quality® L-Citrulline
#4) Maritime Pine Bark Extract
Formed by the harsh salty climes of the sea, maritime pine bark extract supplies proanthocyanidins, a potent class of antioxidants that:
Promote endothelial production of nitric oxide (N.O.)
Protect muscle tissue during intense training
Boost long-term cognitive attentional performance
Look for maritime pine bark extract standardized to 95% proanthocyanidins for optimal results with this unique performance enhancing herbal extract.
#5) Himalayan Pink Salt
Hydration is key to muscle growth, and, yet, when it comes to rehydration, we tend to overlook the importance of electrolytes to sustaining healthy H2O levels. As a natural source of electrolyte trace minerals, Himalayan Pink Salt is a smart choice for restoring sweat-depleted electrolytes when taken in a pre-workout context.
Conclusion
Frankly, our caffeine options are far from limited. If you want caffeine, you can get some. Odds are you’re enjoying a hot cup (or a cold can) of caffeine right now, as you read this, so looking for a caffeine free pre workout or one with caffeine is the choice you have to make.
However, what is hard to come by is a real-deal health and fitness supplement that genuinely supports athletic health and fitness. And with its all-natural, hard-hitting ergogenics packed in its caffeine-free pre-workout formula, Transparent Labs PreSeries Stim-Free Pre-Workout certainly fits the bill.
What’s more, Transparent Labs Stim-Free can be synergistically stacked with other top supplements in Transparent Labs Creatine HMB and Post-Workout.
The point isn’t to completely force you into a caffeine-free workout, but to grant you the option. Head to Transparent Labs to see more formulas with PreSeries Stim-Free Pre-Workout.
Generation Iron may receive commissions on purchases made through our links. See our disclosure page for more information.
Let us know what you think in the comments below. Also, be sure to follow Generation Iron on Facebook, Twitter, and Instagram.
*Images courtesy of Transparent Labs and Envato
References
Cappelletti, S.; et al. (2015). “Caffeine: Cognitive and Physical Performance Enhancer or Psychoactive Drug?”.
Evans J et al. Caffeine. [Updated 2020 Mar 22]. StatPearls. Treasure Island (FL): StatPearls Publishing; 2020 Jan.
Heckman MA et al. Caffeine (1, 3, 7-trimethylxanthine) in Foods: A Comprehensive Review on Consumption, Functionality, Safety, and Regulatory Matters. J Food Sci. 2010 Apr; 75(3): R77-87.
Papadelis C et al. Effects of Mental Workload and Caffeine on Catecholamines and Blood Pressure Compared to Performance Variations. Brain Cogn. 2003 Feb; 51(1): 143-54.
Lovallo WR et al. Cortisol Responses to Mental Stress, Exercise, and Meals Following Caffeine Intake in Men and Women. Pharmacol Biochem Behav. 2006 Mar; 83(3): 441-7.
Volkow ND et al. Caffeine increases striatal dopamine D2/D3receptor availability in the human brain. Transl Psychiatry. 2015 Apr; 5(4): e549.
Souissi M et al. Effects of Morning Caffeine Ingestion on Mood States, Simple Reaction Time, and Short-Term maximal Performance on Elite Judoists. Asian J Sports Med. 2012 Sep; 3(3): 161-168.
Bruce MS, Lader M. Caffeine Abstention in the Management of Anxiety Disorders. Psychol Med. 1989 Feb; 19(1): 211-4.
Astrup A et al. Caffeine: A Double-Blind, Placebo-Controlled Study of Its Thermogenic, Metabolic, and Cardiovascular Effects in Healthy Volunteers. Am J Clin Nutr. 1990 May; 51(5): 759-67.
Drake C et al. Caffeine Effects on Sleep Taken 0, 3, or 6 Hours before Going to Bed. J Clin Sleep Med. 2013 Nov 15; 9(11): 1195-1200.
Echeverri D et al. Caffeine’s Vascular Mechanisms of Action. Int J Vasc Med. 2010; 2010: 834060.
Addicott MA et al. The Effect of Daily Caffeine Use on Cerebral Blood Flow: How Much Caffeine Can We Tolerate?Hum Brain Mapp. 2009 Oct; 30(10): 3102-14.
Cooper R et al. Creatine supplementation with specific view to exercise/sports performance: an update. J Int Soc Sports Nutr. 2012; 9: 33.
Oliver JM et al. Oral Creatine Supplementation’s Decrease of Blood Lactate During Exhaustive, Incremental Cycling. Int J Sport Nutr Exerc Metab. 2013 Jun; 23(3): 252-8.
Hobson RM et al. Effects of ?-alanine supplementation on exercise performance: a meta-analysis. Amino Acids. 2012 Jul; 43(1): 25-37.
McKinley-Barnard S et al. Combined L-citrulline and Glutathione Supplementation Increases the Concentration of Markers Indicative of Nitric Oxide Synthesis. J Int Soc Sports Nutr. 2015 Jun 10; 12: 27.
Maximize your exercise performance without the caffeine crash or jittery brain-drain.
When it comes to stimulants and the best pre workout supplements, there’s really no contest: everyone loves caffeine.
Sure, in our Adderall age, there are certainly more powerful stimulants available. However, for a more sustainable headrush with a limited risk of long-term issues, caffeine remains a reasonable choice for boosting performance, both mentally and physically, and caffeine free pre-workouts are great for this.
Because caffeine is associated with “feel good” performance enhancement, many pre-workout supplements offer generous amounts of caffeine in their formulas, as well as really great vitamins and minerals. However, many of these same supplements tend to mask their poor-quality ingredient forms and overall ineffectiveness with caffeine megadoses, making these failed supplements for those looking for a good caffeine free pre workout supplement.
A few common problems with these cheap, weak supplements include:
As a reliable “dopaminergic” brain booster, caffeine can be used to trick consumers into thinking an inferior, cheap pre-workout supplement is working as they misattribute the noticeable “feel good” feelings of caffeine to the formula’s efficacy.
In this guide, we cover the advantages of avoiding caffeine in your pre-workout stack, as well as how you can optimize yours with the best stim-free ingredients.
But before diving into all of that, here is a deep-dive analysis of Transparent Labs PreSeries Stim-Free Pre-Workout, the best all-in-one caffeine free pre workout.
Best Pre-Workout Without Caffeine: Transparent Labs PreSeries Stim-Free Pre-Workout
Transparent Labs Stim-Free Pre-Workout is a 100% transparent formula great for serious athletes and bodybuilders looking for a high-intensity workout experience without caffeine.
Working with key ingredients like citrulline malate, beta-alanine, taurine, and others, this is a great supplement for those intolerant or avoiding caffeine. With clinically-effective dosages, this is a safe supplement to provide for a host of benefits.
Altogether, Transparent Labs Stim-Free Pre-Workout works by:
Code GENIRON10 For 10% Off
Transparent Labs PreSeries Stim-Free is an amazing option for those looking for stimulant free supplements for strength training, weight loss, and improved performance. With key ingredients at effective dosages, this is a great pre-workout for anyone looking for stim-free options.
Formula Analysis
Compared to the standard hyper-caffeinated pre-workout supplements lining the shelves, this is a smarter, cleaner stack that provides a natural boost with all-natural, stim-free ingredients.
Plus, you don’t get those unwanted jitters or caffeine related side effects that typically ruin a great product. With no stimulants and a transparent label, this supplement also contains no artificial sweeteners, coloring, or preservatives and is gluten-free and non-GMO to truly maximize your athletic fitness and workout performance.
Shop Transparent Labs PreSeries Stim-Free Pre-Workout Here
Stack with Transparent Labs StrengthSeries Creatine HMB and CoreSeries Post-Workout
To maintain consistent progress with your anabolic gains, fat loss, and other fitness-related goals, stacking a caffeine free pre workout supplement with a post-workout supplement and a “rest day” stack can help. A more complete Transparent Labs stack would look like:
Formula Analysis
Altogether, the benefits of Post include:
Code GENIRON10 For 10% Off
Transparent Labs CoreSeries Post is a great supplement to optimize recovery and muscle repair with 6 great ingredients. Paired well with any protein supplement, this can ensure big gains are met.
Transparent Labs StrengthSeries Creatine HMB
Formula Analysis
Altogether, the benefits of Creatine HMB include:
Code GENIRON10 For 10% Off
Transparent Labs Creatine HMB is clean and effective for tackling all of your strength building needs. With no artificial additives or preservatives, what you get is pure creatine with added HMB for better strength.
The World’s Favorite Drug: Caffeine
Coffee, tea, soda, energy drinks, energy shots, pre workout supplements, fat loss supplements, nootropic supplements, energy-boosting gum pack—more and more, it seems like caffeine is sneaking its way into everything these days. And from a seller’s point of view, this makes sense: caffeine makes people feel great, and people buy things that make them feel good (1).
What Exactly Is Caffeine?
Caffeine, or 1,3,7-trimethylxanthine (if you want to get fancy with it), is an alkaloid, which means that its chemical structure is predominated by nitrogen. Pure caffeine is highly water-soluble and can, thus, act rapidly on the brain and body after ingestion without aid of fatty foods (as is the case with fat-soluble compounds) (3). Those sensitive to this strong stimulant would require a caffeine free pre workout for muscle building and lean muscle.
Structurally, caffeine is similar to adenosine, a compound that binds with adenosine receptors to induce cognitive drowsiness and fatigue. Which gives us the perfect segue into the more important question:
What Exactly Does Caffeine Do?
Caffeine, as a compound structurally similar to adenosine, binds to adenosine receptors to block the drowsiness of adenosine. In other words, caffeine achieves its stimulatory properties on the central nervous system (CNS) through its inhibitory effects on adenosine, resulting in a boost on:
The Pros Vs. Cons Of Caffeine For Exercise
Several factors largely determine the advantageous vs. disadvantageous use of caffeine or caffeine free pre workout supplements for the best performance enhancement. However, perhaps the two most important factors are:
Pro #1 – Cognitive Performance
As a dopaminergic stimulant, caffeine may heighten mood and intensity for greater mental motivation in the gym. Taken prior to exercise, caffeine may help ward off mental fatigue in service of a more alert, more ready mindset.
Conversely, the mood- and intensity-boosting advantages of caffeine may also tip over into cognitive impairment by promoting anxiety, nervousness, and jitteriness, which is where a great caffeine free pre-workout would come in handy. Encouraging mental arousal, caffeine may often encourage too much arousal, throwing the mind into a scatterbrained state of anxiety that can be detrimental to athletic performance that requires cool composure.
In addition to boosting cognitive arousal, caffeine’s stimulatory effects also seem to boost thermogenesis, or fat burning. By encouraging the activity of “fight or flight” catecholamines and stress hormones, caffeine seems to heighten the body’s energy expenditure capacity, potentially resulting in greater fat loss results during workouts.
Nothing disrupts performance, endurance, and metabolic health quite like sleep deprivation. Contributing to a wide range of metabolic disorders and performance decrements, poor sleep quality is often associated with excess caffeine use and you won’t necessarily feel these effects with a caffeine free pre workout. And the relationship between the two is a downward spiral: caffeine promotes sleep deprivation, which encourages further caffeine use, and so on.
Caffeine has a vasoconstrictive effect, meaning that this stimulant promotes the constriction of blood vessels, thereby decreasing blood flow. While this sounds like a negative (as we’ll get into in “Con #3” below), caffeine’s vasoconstriction may potentially have a pain-relieving effect on headaches, namely headaches associated with excessive flow to the brain.
One of the main reasons we take pre-workout supplements: boost circulation. And so, naturally, the vasoconstriction of caffeine are typically viewed as a negative when it comes to performance enhancement. Whether we’re talking nootropic cognitive enhancers or bodybuilder pre-workout stacks, the goal is to boost blood flow, not inhibit it and caffeine free pre workouts are great for this.
Okay, So Is Caffeine A Legitimate Performance Enhancer?
Based on the study’s compiled above, the best performance enhancement potential of caffeine significantly depends upon how much caffeine you use, your personal caffeine tolerance, and when you take caffeine (i.e., how close to bedtime) so if sensitive, a caffeine free pre workout would be the way to go.
Of course, much of this is common sense.
But with a better understanding of how caffeine affects your mental and physical performance, you may make a smarter decision as to whether or not you want a caffeine free pre-workout supplement (or any stack for that matter).
An Optional Source Of Pre-Workout Caffeine: Transparent Labs PreSeries BULK Pre-Workout
Code GENIRON10 For 10% Off
Transparent Labs PreSeries BULK is backed by science with clinically effective dosages to increase muscle size and mass. This pre-workout is perfect for reducing fatigue, aiding in muscle growth, and boosting energy levels for better overall performance.
Transparent Labs BULK is the best bulking pre-workout for those looking to gain size and increase muscle mass. With 19 active ingredients and a transparent label, this supplement contains zero artificial sweeteners, flavors, or other additives for only the best in terms of your training and performance.
Top 5 Non-Caffeinated Pre-Workout Ingredients
Whether you’re looking at a caffeinated or caffeine free pre-workout supplement, some of the best pre-workout ingredients you need to look for include:
#1) Creatine
An organic compound highly concentrated in tissue, creatine works as precursor fuel for the natural production of ATP energy, a cleaner, more natural energy source than the stimulatory effects of caffeine. As a dietary supplement, it boosts exercise performance by (13,14):
Best Pre-Workout Creatine: Creapure® pH10
A well-known sports nutrition aid, namely for the skin-tingling sensation associated with it, Beta-Alanine replenishes levels of carnosine, a dipeptide molecule, in muscle tissue, namely fast-twitch fibers for increased strength and power during high-intensity exercise. Consistently loading and maintaining, carnosine benefits performance and recuperation by (15):
Best Pre-Workout Beta-Alanine: CarnoSyn®
#3) L-Citrulline + L-Glutathione
L-Citrulline is an amino acid that, once absorbed, converts in the body to L-arginine, a nitric oxide (N.O.) booster that enhances muscular circulation, strength, and growth. In other words, L-citrulline works as your go-to pre-workout “muscle pump” booster and will help with mind-muscle connection.
Additionally, L-Glutathione is an antioxidant enzyme that, when paired with L-citrulline, benefits performance in a few ways. Combined, L-citrulline + L-glutathione work by (16):
Best Pre-Workout L-Citrulline + L-Glutathione: Setria® Performance Blend
Formed by the harsh salty climes of the sea, maritime pine bark extract supplies proanthocyanidins, a potent class of antioxidants that:
#5) Himalayan Pink Salt
Hydration is key to muscle growth, and, yet, when it comes to rehydration, we tend to overlook the importance of electrolytes to sustaining healthy H2O levels. As a natural source of electrolyte trace minerals, Himalayan Pink Salt is a smart choice for restoring sweat-depleted electrolytes when taken in a pre-workout context.
Conclusion
Frankly, our caffeine options are far from limited. If you want caffeine, you can get some. Odds are you’re enjoying a hot cup (or a cold can) of caffeine right now, as you read this, so looking for a caffeine free pre workout or one with caffeine is the choice you have to make.
However, what is hard to come by is a real-deal health and fitness supplement that genuinely supports athletic health and fitness. And with its all-natural, hard-hitting ergogenics packed in its caffeine-free pre-workout formula, Transparent Labs PreSeries Stim-Free Pre-Workout certainly fits the bill.
What’s more, Transparent Labs Stim-Free can be synergistically stacked with other top supplements in Transparent Labs Creatine HMB and Post-Workout.
The point isn’t to completely force you into a caffeine-free workout, but to grant you the option. Head to Transparent Labs to see more formulas with PreSeries Stim-Free Pre-Workout.
Generation Iron may receive commissions on purchases made through our links. See our disclosure page for more information.
Let us know what you think in the comments below. Also, be sure to follow Generation Iron on Facebook, Twitter, and Instagram.
*Images courtesy of Transparent Labs and Envato
References
[*]Cappelletti, S.; et al. (2015). “Caffeine: Cognitive and Physical Performance Enhancer or Psychoactive Drug?”.
[*]Evans J et al. Caffeine. [Updated 2020 Mar 22]. StatPearls. Treasure Island (FL): StatPearls Publishing; 2020 Jan.
[*]Heckman MA et al. Caffeine (1, 3, 7-trimethylxanthine) in Foods: A Comprehensive Review on Consumption, Functionality, Safety, and Regulatory Matters. J Food Sci. 2010 Apr; 75(3): R77-87.
[*]Papadelis C et al. Effects of Mental Workload and Caffeine on Catecholamines and Blood Pressure Compared to Performance Variations. Brain Cogn. 2003 Feb; 51(1): 143-54.
[*]Lovallo WR et al. Cortisol Responses to Mental Stress, Exercise, and Meals Following Caffeine Intake in Men and Women. Pharmacol Biochem Behav. 2006 Mar; 83(3): 441-7.
[*]Volkow ND et al. Caffeine increases striatal dopamine D2/D3receptor availability in the human brain. Transl Psychiatry. 2015 Apr; 5(4): e549.
[*]Souissi M et al. Effects of Morning Caffeine Ingestion on Mood States, Simple Reaction Time, and Short-Term maximal Performance on Elite Judoists. Asian J Sports Med. 2012 Sep; 3(3): 161-168.
[*]Bruce MS, Lader M. Caffeine Abstention in the Management of Anxiety Disorders. Psychol Med. 1989 Feb; 19(1): 211-4.
[*]Astrup A et al. Caffeine: A Double-Blind, Placebo-Controlled Study of Its Thermogenic, Metabolic, and Cardiovascular Effects in Healthy Volunteers. Am J Clin Nutr. 1990 May; 51(5): 759-67.
[*]Drake C et al. Caffeine Effects on Sleep Taken 0, 3, or 6 Hours before Going to Bed. J Clin Sleep Med. 2013 Nov 15; 9(11): 1195-1200.
[*]Echeverri D et al. Caffeine’s Vascular Mechanisms of Action. Int J Vasc Med. 2010; 2010: 834060.
[*]Addicott MA et al. The Effect of Daily Caffeine Use on Cerebral Blood Flow: How Much Caffeine Can We Tolerate?Hum Brain Mapp. 2009 Oct; 30(10): 3102-14.
[*]Cooper R et al. Creatine supplementation with specific view to exercise/sports performance: an update. J Int Soc Sports Nutr. 2012; 9: 33.
[*]Oliver JM et al. Oral Creatine Supplementation’s Decrease of Blood Lactate During Exhaustive, Incremental Cycling. Int J Sport Nutr Exerc Metab. 2013 Jun; 23(3): 252-8.
[*]Hobson RM et al. Effects of ?-alanine supplementation on exercise performance: a meta-analysis. Amino Acids. 2012 Jul; 43(1): 25-37.
[*]McKinley-Barnard S et al. Combined L-citrulline and Glutathione Supplementation Increases the Concentration of Markers Indicative of Nitric Oxide Synthesis. J Int Soc Sports Nutr. 2015 Jun 10; 12: 27.
Click here to view the article.
When it comes to stimulants and the best pre workout supplements, there’s really no contest: everyone loves caffeine.
Sure, in our Adderall age, there are certainly more powerful stimulants available. However, for a more sustainable headrush with a limited risk of long-term issues, caffeine remains a reasonable choice for boosting performance, both mentally and physically, and caffeine free pre-workouts are great for this.
Because caffeine is associated with “feel good” performance enhancement, many pre-workout supplements offer generous amounts of caffeine in their formulas, as well as really great vitamins and minerals. However, many of these same supplements tend to mask their poor-quality ingredient forms and overall ineffectiveness with caffeine megadoses, making these failed supplements for those looking for a good caffeine free pre workout supplement.
A few common problems with these cheap, weak supplements include:
Jitters related to excess stimulation
Poor absorption due to excess caffeine
Low-grade creatine forms linked to gastric distress
Unhealthy, pointless synthetic flavors and artificial additives
And more. In other words, caffeine isn’t the only problem with today’s standard pre-workout formula; although, it does often distinguish effective caffeine free pre-workout stacks from ineffective formulas.
As a reliable “dopaminergic” brain booster, caffeine can be used to trick consumers into thinking an inferior, cheap pre-workout supplement is working as they misattribute the noticeable “feel good” feelings of caffeine to the formula’s efficacy.
In this guide, we cover the advantages of avoiding caffeine in your pre-workout stack, as well as how you can optimize yours with the best stim-free ingredients.
But before diving into all of that, here is a deep-dive analysis of Transparent Labs PreSeries Stim-Free Pre-Workout, the best all-in-one caffeine free pre workout.
Best Pre-Workout Without Caffeine: Transparent Labs PreSeries Stim-Free Pre-Workout
Transparent Labs Stim-Free Pre-Workout is a 100% transparent formula great for serious athletes and bodybuilders looking for a high-intensity workout experience without caffeine.
Working with key ingredients like citrulline malate, beta-alanine, taurine, and others, this is a great supplement for those intolerant or avoiding caffeine. With clinically-effective dosages, this is a safe supplement to provide for a host of benefits.
Altogether, Transparent Labs Stim-Free Pre-Workout works by:
Increasing nitric oxide to the muscles to support enhanced muscular blood flow and oxygenation, priming the “muscle pump” feel for every great workout.
Enhancing focus to give raise alertness so you stay engaged throughout the entire workout.
Boosting endurance by working as a buffer for lactic acid build up and giving you a great endurance boost.
Promoting lean muscle growth for increased strength and definition for better training, performance, and that desired aesthetic.
Plus, with a transparent label and safe, effective ingredients, you know exactly what you are putting into your body.
Code GENIRON10 For 10% Off
Transparent Labs PreSeries Stim-Free is an amazing option for those looking for stimulant free supplements for strength training, weight loss, and improved performance. With key ingredients at effective dosages, this is a great pre-workout for anyone looking for stim-free options.
Formula Analysis
Citrulline Malate 2:1, 6,000mg
BCAA 2:1:1, 4,000mg
Beta-Alanine, 4,000mg
BetaPure Betaine Anhydrous, 2,500mg
Taurine, 1,300mg
L-Tyrosine, 1,000mg
Choline Bitartrate, 500mg
ElevATP Ancient Peat and Apple Fruit Extract, 150mg
BioPerine, 5mg
Huperzine A, 50mcg
Transparent Labs Stim-Free brings strength and endurance gains to a whole new level with a unique combination of highly potent, bioavailable, and caffeine-free pre-workout ingredients.
Compared to the standard hyper-caffeinated pre-workout supplements lining the shelves, this is a smarter, cleaner stack that provides a natural boost with all-natural, stim-free ingredients.
Plus, you don’t get those unwanted jitters or caffeine related side effects that typically ruin a great product. With no stimulants and a transparent label, this supplement also contains no artificial sweeteners, coloring, or preservatives and is gluten-free and non-GMO to truly maximize your athletic fitness and workout performance.
Shop Transparent Labs PreSeries Stim-Free Pre-Workout Here
[embedded content]
Stack with Transparent Labs StrengthSeries Creatine HMB and CoreSeries Post-Workout
To maintain consistent progress with your anabolic gains, fat loss, and other fitness-related goals, stacking a caffeine free pre workout supplement with a post-workout supplement and a “rest day” stack can help. A more complete Transparent Labs stack would look like:
Stim-Free Pre-Workout– a caffeine-free pre-workout enhancer designed to boost nitric oxide, muscle strength, and endurance.
Post– a post-workout formula designed to promote anabolic muscle gains and protect against muscle breakdown.
Creatine HMB– a creatine supplement perfect for restoring depleted muscle tissue and increasing strength.
Transparent Labs CoreSeries Post-Workout
Formula Analysis
L-Glutamine, 5,000mg
Betaine Anhydrous, 2,500mg
L-Carnitine L-Tartrate, 2,000mg
Beta-Alanine, 2,000mg
Tart Cherry Powder, 500mg
Astragin, 25mg
Transparent Labs Post is a great post-workout supplement to maximize muscle growth and see results immediately. Working to optimize recovery and muscle repair, the body needs targeted nutrients to fully recharge that are backed by science. With Post, you get great ingredients working together for the best results.
Altogether, the benefits of Post include:
Bolster nitric oxide production
Reduce delayed-onset muscle soreness
Facilitate protein synthesis
Enhance insulin sensitivity
Prime your body for growth and recovery
Code GENIRON10 For 10% Off
Transparent Labs CoreSeries Post is a great supplement to optimize recovery and muscle repair with 6 great ingredients. Paired well with any protein supplement, this can ensure big gains are met.
Transparent Labs StrengthSeries Creatine HMB
Formula Analysis
Creapure Creatine Monohydrate, 5,000mg
B-Hydroxy B-Methylbutyrate (HMB), 1,500mg
BioPerine Black Pepper Extract, 5mg
Transparent Labs Creatine HMB will work to boost performance without losing those hard-earned gains. The added ingredient of HMB along with creatine works in tandem to promote growth, recovery, and provide for the best results possible. BioPerine is exactly what you need to increase absorption so nothing goes to waste.
Altogether, the benefits of Creatine HMB include:
Promote strength and lean muscle
Increase endurance
Prevent lean muscle loss
Decrease fat mass
Code GENIRON10 For 10% Off
Transparent Labs Creatine HMB is clean and effective for tackling all of your strength building needs. With no artificial additives or preservatives, what you get is pure creatine with added HMB for better strength.
The World’s Favorite Drug: Caffeine
Coffee, tea, soda, energy drinks, energy shots, pre workout supplements, fat loss supplements, nootropic supplements, energy-boosting gum pack—more and more, it seems like caffeine is sneaking its way into everything these days. And from a seller’s point of view, this makes sense: caffeine makes people feel great, and people buy things that make them feel good (1).
What’s more, caffeine makes people feel good in a reliable way that’s relatively safe to other habit-forming stimulants and quote-unquote “drugs.”
As a naturally occurring compound, caffeine is found in roughly sixty different plant species, including (2):
Coffee Beans
Tea Leaves
Cocoa Beans
Kola Nuts
Yerba Maté
Guarana Berries
Guayusa
Yaupon Holly
Which is interesting and all, but the more important question here is:
What Exactly Is Caffeine?
Caffeine, or 1,3,7-trimethylxanthine (if you want to get fancy with it), is an alkaloid, which means that its chemical structure is predominated by nitrogen. Pure caffeine is highly water-soluble and can, thus, act rapidly on the brain and body after ingestion without aid of fatty foods (as is the case with fat-soluble compounds) (3). Those sensitive to this strong stimulant would require a caffeine free pre workout for muscle building and lean muscle.
Structurally, caffeine is similar to adenosine, a compound that binds with adenosine receptors to induce cognitive drowsiness and fatigue. Which gives us the perfect segue into the more important question:
What Exactly Does Caffeine Do?
Caffeine, as a compound structurally similar to adenosine, binds to adenosine receptors to block the drowsiness of adenosine. In other words, caffeine achieves its stimulatory properties on the central nervous system (CNS) through its inhibitory effects on adenosine, resulting in a boost on:
Catecholamines – dopamine, norepinephrine, epinephrine, etc. (4).
Adrenal Activity– encouraging the release of stress hormone cortisol (5).
Dopamine Signaling – in high dosages (300+ mg), caffeine may increase the availability of dopamine receptors (6).
The Pros Vs. Cons Of Caffeine For Exercise
Several factors largely determine the advantageous vs. disadvantageous use of caffeine or caffeine free pre workout supplements for the best performance enhancement. However, perhaps the two most important factors are:
Dosage – the amount of caffeine per serving
Timing– when you take caffeine (i.e., morning or night?)
Caffeine Sensitivity– your personal tolerance to stimulants
Some people are more sensitive to caffeine than others, and therefore they require smaller dosages to reach peak effect. Others may feel like they need to guzzle a significant amount of caffeine just to reach their cognitive baseline so knowing the pros and cons is huge.
Pro #1 – Cognitive Performance
As a dopaminergic stimulant, caffeine may heighten mood and intensity for greater mental motivation in the gym. Taken prior to exercise, caffeine may help ward off mental fatigue in service of a more alert, more ready mindset.
Study: in a placebo-controlled study on caffeine consumption on judo athletes, morning caffeine ingestion was suggested to have “ergogenic properties with the potential to benefit performance, increase anxiety and vigor, and decrease the simple reaction time” (7).
Con #1 – Anxiety, Nervousness, and Jitteriness
Conversely, the mood- and intensity-boosting advantages of caffeine may also tip over into cognitive impairment by promoting anxiety, nervousness, and jitteriness, which is where a great caffeine free pre-workout would come in handy. Encouraging mental arousal, caffeine may often encourage too much arousal, throwing the mind into a scatterbrained state of anxiety that can be detrimental to athletic performance that requires cool composure.
Study: under conditions of anxiety disorder, caffeine consumption may exacerbate anxiety symptoms, potentially as a consequence of increased sensitivity to caffeine associated with anxiety disorder (8). Abstaining from caffeine altogether may significantly help maintain a level head under such conditions.
Pro #2 – Thermogenic Fat Loss
In addition to boosting cognitive arousal, caffeine’s stimulatory effects also seem to boost thermogenesis, or fat burning. By encouraging the activity of “fight or flight” catecholamines and stress hormones, caffeine seems to heighten the body’s energy expenditure capacity, potentially resulting in greater fat loss results during workouts.
Study: in one double-blind, placebo-controlled study, 100, 200, and 400 mg caffeine dosages were observed to determine what happened with thermogenic, metabolic, and cardio health measures. The results: caffeine dose-dependently increased thermogenic energy expenditure in association with increased plasma lactate and triglyceride levels (9).
Con #2 – Poor Sleep Quality
Nothing disrupts performance, endurance, and metabolic health quite like sleep deprivation. Contributing to a wide range of metabolic disorders and performance decrements, poor sleep quality is often associated with excess caffeine use and you won’t necessarily feel these effects with a caffeine free pre workout. And the relationship between the two is a downward spiral: caffeine promotes sleep deprivation, which encourages further caffeine use, and so on.
Study: comparing the sleep disruptive effects of caffeine administered at 0, 3, and 6 hours prior to bedtime, a group of researchers observed that “caffeine taken 6 hours before bedtime has important disruptive properties on sleep and provides empirical support for sleep hygiene recommendations to refrain from substantial caffeine use for a minimum of 6 hours prior to bedtime” (10).
Pro #3 – Vasoconstriction
Caffeine has a vasoconstrictive effect, meaning that this stimulant promotes the constriction of blood vessels, thereby decreasing blood flow. While this sounds like a negative (as we’ll get into in “Con #3” below), caffeine’s vasoconstriction may potentially have a pain-relieving effect on headaches, namely headaches associated with excessive flow to the brain.
Study: as one study on caffeine’s vascular mechanisms of action suggests, “caffeine has some cardiovascular properties and effects which could be considered beneficial,” (11) involving the association between decreased cerebral circulation and migrainous headache.
Con #3 – Vasoconstriction
One of the main reasons we take pre-workout supplements: boost circulation. And so, naturally, the vasoconstriction of caffeine are typically viewed as a negative when it comes to performance enhancement. Whether we’re talking nootropic cognitive enhancers or bodybuilder pre-workout stacks, the goal is to boost blood flow, not inhibit it and caffeine free pre workouts are great for this.
Study: in one 2009 study on the effects of daily caffeine use on cerebral blood flow, caffeine was shown to reduce cerebral blood flow by an average 27%, (12) which may significantly impact cognition and goes against the vasodilatory aims of pre-workout N.O. boosters.
Okay, So Is Caffeine A Legitimate Performance Enhancer?
Based on the study’s compiled above, the best performance enhancement potential of caffeine significantly depends upon how much caffeine you use, your personal caffeine tolerance, and when you take caffeine (i.e., how close to bedtime) so if sensitive, a caffeine free pre workout would be the way to go.
Of course, much of this is common sense.
But with a better understanding of how caffeine affects your mental and physical performance, you may make a smarter decision as to whether or not you want a caffeine free pre-workout supplement (or any stack for that matter).
An Optional Source Of Pre-Workout Caffeine: Transparent Labs PreSeries BULK Pre-Workout
Code GENIRON10 For 10% Off
Transparent Labs PreSeries BULK is backed by science with clinically effective dosages to increase muscle size and mass. This pre-workout is perfect for reducing fatigue, aiding in muscle growth, and boosting energy levels for better overall performance.
Transparent Labs BULK is the best bulking pre-workout for those looking to gain size and increase muscle mass. With 19 active ingredients and a transparent label, this supplement contains zero artificial sweeteners, flavors, or other additives for only the best in terms of your training and performance.
Top 5 Non-Caffeinated Pre-Workout Ingredients
Whether you’re looking at a caffeinated or caffeine free pre-workout supplement, some of the best pre-workout ingredients you need to look for include:
#1) Creatine
An organic compound highly concentrated in tissue, creatine works as precursor fuel for the natural production of ATP energy, a cleaner, more natural energy source than the stimulatory effects of caffeine. As a dietary supplement, it boosts exercise performance by (13,14):
Replenishing exercise-depleted ATP energy
Stimulating insulin-like growth factor 1 (IGF-1)
Buffering muscular lactic acid build-up for better endurance
Because creatine concentrates in muscle tissue, ongoing supplementation is required for creatine to reach peak saturation and, thus, peak ergogenic effect.
Best Pre-Workout Creatine: Creapure® pH10
Creapure® pH10 is 99.5% pure creatine monohydrate
pH-balanced to enhance bioavailability
Clean and easy-to-absorb to reduce bloating and gastric distress
#2) Beta-Alanine
A well-known sports nutrition aid, namely for the skin-tingling sensation associated with it, Beta-Alanine replenishes levels of carnosine, a dipeptide molecule, in muscle tissue, namely fast-twitch fibers for increased strength and power during high-intensity exercise. Consistently loading and maintaining, carnosine benefits performance and recuperation by (15):
Delaying onset fatigue and failure
Enhancing overall strength and stamina
Neutralizing exercise-induced free radicals
Inhibiting advanced glycation end-products (AGEs)
Buffering the impact of damaging acids
And more. The strength and endurance benefits of beta-alanine are unmatched and pair incredibly well with the endurance-boosting advantages of creatine supplementation and caffeine free pre workout.
Best Pre-Workout Beta-Alanine: CarnoSyn®
CarnoSyn® is the only beta-alanine with NDI (New Dietary Ingredient) status
Generally Recognized as Safe (GRAS)
Well-backed by years of clinical research
#3) L-Citrulline + L-Glutathione
L-Citrulline is an amino acid that, once absorbed, converts in the body to L-arginine, a nitric oxide (N.O.) booster that enhances muscular circulation, strength, and growth. In other words, L-citrulline works as your go-to pre-workout “muscle pump” booster and will help with mind-muscle connection.
Additionally, L-Glutathione is an antioxidant enzyme that, when paired with L-citrulline, benefits performance in a few ways. Combined, L-citrulline + L-glutathione work by (16):
Promoting oxygen delivery to tissue
Protecting muscle against oxidative stress
Sustaining L-citrulline’s N.O.-boosting bioactivities
Improving energy and anabolism
Strengthening immunity against gym-related challenges
And more. Stacking these two compounds may significantly boost performance and protect against the deleterious side effects of boosted performance.
Best Pre-Workout L-Citrulline + L-Glutathione: Setria® Performance Blend
Setria® Performance Blend is made by Kyowa Hakko Bio Co. Ltd., a world leader in supplement development
Kyowa Quality® L-Citrulline is exceptionally clean and bioavailable
Setria® is an advanced glutathione form that pairs well with Kyowa Quality® L-Citrulline
#4) Maritime Pine Bark Extract
Formed by the harsh salty climes of the sea, maritime pine bark extract supplies proanthocyanidins, a potent class of antioxidants that:
Promote endothelial production of nitric oxide (N.O.)
Protect muscle tissue during intense training
Boost long-term cognitive attentional performance
Look for maritime pine bark extract standardized to 95% proanthocyanidins for optimal results with this unique performance enhancing herbal extract.
#5) Himalayan Pink Salt
Hydration is key to muscle growth, and, yet, when it comes to rehydration, we tend to overlook the importance of electrolytes to sustaining healthy H2O levels. As a natural source of electrolyte trace minerals, Himalayan Pink Salt is a smart choice for restoring sweat-depleted electrolytes when taken in a pre-workout context.
Conclusion
Frankly, our caffeine options are far from limited. If you want caffeine, you can get some. Odds are you’re enjoying a hot cup (or a cold can) of caffeine right now, as you read this, so looking for a caffeine free pre workout or one with caffeine is the choice you have to make.
However, what is hard to come by is a real-deal health and fitness supplement that genuinely supports athletic health and fitness. And with its all-natural, hard-hitting ergogenics packed in its caffeine-free pre-workout formula, Transparent Labs PreSeries Stim-Free Pre-Workout certainly fits the bill.
What’s more, Transparent Labs Stim-Free can be synergistically stacked with other top supplements in Transparent Labs Creatine HMB and Post-Workout.
The point isn’t to completely force you into a caffeine-free workout, but to grant you the option. Head to Transparent Labs to see more formulas with PreSeries Stim-Free Pre-Workout.
Generation Iron may receive commissions on purchases made through our links. See our disclosure page for more information.
Let us know what you think in the comments below. Also, be sure to follow Generation Iron on Facebook, Twitter, and Instagram.
*Images courtesy of Transparent Labs and Envato
References
Cappelletti, S.; et al. (2015). “Caffeine: Cognitive and Physical Performance Enhancer or Psychoactive Drug?”.
Evans J et al. Caffeine. [Updated 2020 Mar 22]. StatPearls. Treasure Island (FL): StatPearls Publishing; 2020 Jan.
Heckman MA et al. Caffeine (1, 3, 7-trimethylxanthine) in Foods: A Comprehensive Review on Consumption, Functionality, Safety, and Regulatory Matters. J Food Sci. 2010 Apr; 75(3): R77-87.
Papadelis C et al. Effects of Mental Workload and Caffeine on Catecholamines and Blood Pressure Compared to Performance Variations. Brain Cogn. 2003 Feb; 51(1): 143-54.
Lovallo WR et al. Cortisol Responses to Mental Stress, Exercise, and Meals Following Caffeine Intake in Men and Women. Pharmacol Biochem Behav. 2006 Mar; 83(3): 441-7.
Volkow ND et al. Caffeine increases striatal dopamine D2/D3receptor availability in the human brain. Transl Psychiatry. 2015 Apr; 5(4): e549.
Souissi M et al. Effects of Morning Caffeine Ingestion on Mood States, Simple Reaction Time, and Short-Term maximal Performance on Elite Judoists. Asian J Sports Med. 2012 Sep; 3(3): 161-168.
Bruce MS, Lader M. Caffeine Abstention in the Management of Anxiety Disorders. Psychol Med. 1989 Feb; 19(1): 211-4.
Astrup A et al. Caffeine: A Double-Blind, Placebo-Controlled Study of Its Thermogenic, Metabolic, and Cardiovascular Effects in Healthy Volunteers. Am J Clin Nutr. 1990 May; 51(5): 759-67.
Drake C et al. Caffeine Effects on Sleep Taken 0, 3, or 6 Hours before Going to Bed. J Clin Sleep Med. 2013 Nov 15; 9(11): 1195-1200.
Echeverri D et al. Caffeine’s Vascular Mechanisms of Action. Int J Vasc Med. 2010; 2010: 834060.
Addicott MA et al. The Effect of Daily Caffeine Use on Cerebral Blood Flow: How Much Caffeine Can We Tolerate?Hum Brain Mapp. 2009 Oct; 30(10): 3102-14.
Cooper R et al. Creatine supplementation with specific view to exercise/sports performance: an update. J Int Soc Sports Nutr. 2012; 9: 33.
Oliver JM et al. Oral Creatine Supplementation’s Decrease of Blood Lactate During Exhaustive, Incremental Cycling. Int J Sport Nutr Exerc Metab. 2013 Jun; 23(3): 252-8.
Hobson RM et al. Effects of ?-alanine supplementation on exercise performance: a meta-analysis. Amino Acids. 2012 Jul; 43(1): 25-37.
McKinley-Barnard S et al. Combined L-citrulline and Glutathione Supplementation Increases the Concentration of Markers Indicative of Nitric Oxide Synthesis. J Int Soc Sports Nutr. 2015 Jun 10; 12: 27.
Maximize your exercise performance without the caffeine crash or jittery brain-drain.
When it comes to stimulants and the best pre workout supplements, there’s really no contest: everyone loves caffeine.
Sure, in our Adderall age, there are certainly more powerful stimulants available. However, for a more sustainable headrush with a limited risk of long-term issues, caffeine remains a reasonable choice for boosting performance, both mentally and physically, and caffeine free pre-workouts are great for this.
Because caffeine is associated with “feel good” performance enhancement, many pre-workout supplements offer generous amounts of caffeine in their formulas, as well as really great vitamins and minerals. However, many of these same supplements tend to mask their poor-quality ingredient forms and overall ineffectiveness with caffeine megadoses, making these failed supplements for those looking for a good caffeine free pre workout supplement.
A few common problems with these cheap, weak supplements include:
- Jitters related to excess stimulation
- Poor absorption due to excess caffeine
- Low-grade creatine forms linked to gastric distress
- Unhealthy, pointless synthetic flavors and artificial additives
As a reliable “dopaminergic” brain booster, caffeine can be used to trick consumers into thinking an inferior, cheap pre-workout supplement is working as they misattribute the noticeable “feel good” feelings of caffeine to the formula’s efficacy.
In this guide, we cover the advantages of avoiding caffeine in your pre-workout stack, as well as how you can optimize yours with the best stim-free ingredients.
But before diving into all of that, here is a deep-dive analysis of Transparent Labs PreSeries Stim-Free Pre-Workout, the best all-in-one caffeine free pre workout.
Best Pre-Workout Without Caffeine: Transparent Labs PreSeries Stim-Free Pre-Workout
Transparent Labs Stim-Free Pre-Workout is a 100% transparent formula great for serious athletes and bodybuilders looking for a high-intensity workout experience without caffeine.
Working with key ingredients like citrulline malate, beta-alanine, taurine, and others, this is a great supplement for those intolerant or avoiding caffeine. With clinically-effective dosages, this is a safe supplement to provide for a host of benefits.
Altogether, Transparent Labs Stim-Free Pre-Workout works by:
- Increasing nitric oxide to the muscles to support enhanced muscular blood flow and oxygenation, priming the “muscle pump” feel for every great workout.
- Enhancing focus to give raise alertness so you stay engaged throughout the entire workout.
- Boosting endurance by working as a buffer for lactic acid build up and giving you a great endurance boost.
- Promoting lean muscle growth for increased strength and definition for better training, performance, and that desired aesthetic.
Code GENIRON10 For 10% Off
Transparent Labs PreSeries Stim-Free is an amazing option for those looking for stimulant free supplements for strength training, weight loss, and improved performance. With key ingredients at effective dosages, this is a great pre-workout for anyone looking for stim-free options.
Formula Analysis
- Citrulline Malate 2:1, 6,000mg
- BCAA 2:1:1, 4,000mg
- Beta-Alanine, 4,000mg
- BetaPure Betaine Anhydrous, 2,500mg
- Taurine, 1,300mg
- L-Tyrosine, 1,000mg
- Choline Bitartrate, 500mg
- ElevATP Ancient Peat and Apple Fruit Extract, 150mg
- BioPerine, 5mg
- Huperzine A, 50mcg
Compared to the standard hyper-caffeinated pre-workout supplements lining the shelves, this is a smarter, cleaner stack that provides a natural boost with all-natural, stim-free ingredients.
Plus, you don’t get those unwanted jitters or caffeine related side effects that typically ruin a great product. With no stimulants and a transparent label, this supplement also contains no artificial sweeteners, coloring, or preservatives and is gluten-free and non-GMO to truly maximize your athletic fitness and workout performance.
Shop Transparent Labs PreSeries Stim-Free Pre-Workout Here
Stack with Transparent Labs StrengthSeries Creatine HMB and CoreSeries Post-Workout
To maintain consistent progress with your anabolic gains, fat loss, and other fitness-related goals, stacking a caffeine free pre workout supplement with a post-workout supplement and a “rest day” stack can help. A more complete Transparent Labs stack would look like:
- Stim-Free Pre-Workout– a caffeine-free pre-workout enhancer designed to boost nitric oxide, muscle strength, and endurance.
- Post– a post-workout formula designed to promote anabolic muscle gains and protect against muscle breakdown.
- Creatine HMB– a creatine supplement perfect for restoring depleted muscle tissue and increasing strength.
Formula Analysis
- L-Glutamine, 5,000mg
- Betaine Anhydrous, 2,500mg
- L-Carnitine L-Tartrate, 2,000mg
- Beta-Alanine, 2,000mg
- Tart Cherry Powder, 500mg
- Astragin, 25mg
Altogether, the benefits of Post include:
- Bolster nitric oxide production
- Reduce delayed-onset muscle soreness
- Facilitate protein synthesis
- Enhance insulin sensitivity
- Prime your body for growth and recovery
Code GENIRON10 For 10% Off
Transparent Labs CoreSeries Post is a great supplement to optimize recovery and muscle repair with 6 great ingredients. Paired well with any protein supplement, this can ensure big gains are met.
Transparent Labs StrengthSeries Creatine HMB
Formula Analysis
- Creapure Creatine Monohydrate, 5,000mg
- B-Hydroxy B-Methylbutyrate (HMB), 1,500mg
- BioPerine Black Pepper Extract, 5mg
Altogether, the benefits of Creatine HMB include:
- Promote strength and lean muscle
- Increase endurance
- Prevent lean muscle loss
- Decrease fat mass
Code GENIRON10 For 10% Off
Transparent Labs Creatine HMB is clean and effective for tackling all of your strength building needs. With no artificial additives or preservatives, what you get is pure creatine with added HMB for better strength.
The World’s Favorite Drug: Caffeine
Coffee, tea, soda, energy drinks, energy shots, pre workout supplements, fat loss supplements, nootropic supplements, energy-boosting gum pack—more and more, it seems like caffeine is sneaking its way into everything these days. And from a seller’s point of view, this makes sense: caffeine makes people feel great, and people buy things that make them feel good (1).
- What’s more, caffeine makes people feel good in a reliable way that’s relatively safe to other habit-forming stimulants and quote-unquote “drugs.”
- Coffee Beans
- Tea Leaves
- Cocoa Beans
- Kola Nuts
- Yerba Maté
- Guarana Berries
- Guayusa
- Yaupon Holly
What Exactly Is Caffeine?
Caffeine, or 1,3,7-trimethylxanthine (if you want to get fancy with it), is an alkaloid, which means that its chemical structure is predominated by nitrogen. Pure caffeine is highly water-soluble and can, thus, act rapidly on the brain and body after ingestion without aid of fatty foods (as is the case with fat-soluble compounds) (3). Those sensitive to this strong stimulant would require a caffeine free pre workout for muscle building and lean muscle.
Structurally, caffeine is similar to adenosine, a compound that binds with adenosine receptors to induce cognitive drowsiness and fatigue. Which gives us the perfect segue into the more important question:
What Exactly Does Caffeine Do?
Caffeine, as a compound structurally similar to adenosine, binds to adenosine receptors to block the drowsiness of adenosine. In other words, caffeine achieves its stimulatory properties on the central nervous system (CNS) through its inhibitory effects on adenosine, resulting in a boost on:
- Catecholamines – dopamine, norepinephrine, epinephrine, etc. (4).
- Adrenal Activity– encouraging the release of stress hormone cortisol (5).
- Dopamine Signaling – in high dosages (300+ mg), caffeine may increase the availability of dopamine receptors (6).
The Pros Vs. Cons Of Caffeine For Exercise
Several factors largely determine the advantageous vs. disadvantageous use of caffeine or caffeine free pre workout supplements for the best performance enhancement. However, perhaps the two most important factors are:
- Dosage – the amount of caffeine per serving
- Timing– when you take caffeine (i.e., morning or night?)
- Caffeine Sensitivity– your personal tolerance to stimulants
Pro #1 – Cognitive Performance
As a dopaminergic stimulant, caffeine may heighten mood and intensity for greater mental motivation in the gym. Taken prior to exercise, caffeine may help ward off mental fatigue in service of a more alert, more ready mindset.
- Study: in a placebo-controlled study on caffeine consumption on judo athletes, morning caffeine ingestion was suggested to have “ergogenic properties with the potential to benefit performance, increase anxiety and vigor, and decrease the simple reaction time” (7).
Conversely, the mood- and intensity-boosting advantages of caffeine may also tip over into cognitive impairment by promoting anxiety, nervousness, and jitteriness, which is where a great caffeine free pre-workout would come in handy. Encouraging mental arousal, caffeine may often encourage too much arousal, throwing the mind into a scatterbrained state of anxiety that can be detrimental to athletic performance that requires cool composure.
- Study: under conditions of anxiety disorder, caffeine consumption may exacerbate anxiety symptoms, potentially as a consequence of increased sensitivity to caffeine associated with anxiety disorder (8). Abstaining from caffeine altogether may significantly help maintain a level head under such conditions.
In addition to boosting cognitive arousal, caffeine’s stimulatory effects also seem to boost thermogenesis, or fat burning. By encouraging the activity of “fight or flight” catecholamines and stress hormones, caffeine seems to heighten the body’s energy expenditure capacity, potentially resulting in greater fat loss results during workouts.
- Study: in one double-blind, placebo-controlled study, 100, 200, and 400 mg caffeine dosages were observed to determine what happened with thermogenic, metabolic, and cardio health measures. The results: caffeine dose-dependently increased thermogenic energy expenditure in association with increased plasma lactate and triglyceride levels (9).
Nothing disrupts performance, endurance, and metabolic health quite like sleep deprivation. Contributing to a wide range of metabolic disorders and performance decrements, poor sleep quality is often associated with excess caffeine use and you won’t necessarily feel these effects with a caffeine free pre workout. And the relationship between the two is a downward spiral: caffeine promotes sleep deprivation, which encourages further caffeine use, and so on.
- Study: comparing the sleep disruptive effects of caffeine administered at 0, 3, and 6 hours prior to bedtime, a group of researchers observed that “caffeine taken 6 hours before bedtime has important disruptive properties on sleep and provides empirical support for sleep hygiene recommendations to refrain from substantial caffeine use for a minimum of 6 hours prior to bedtime” (10).
Caffeine has a vasoconstrictive effect, meaning that this stimulant promotes the constriction of blood vessels, thereby decreasing blood flow. While this sounds like a negative (as we’ll get into in “Con #3” below), caffeine’s vasoconstriction may potentially have a pain-relieving effect on headaches, namely headaches associated with excessive flow to the brain.
- Study: as one study on caffeine’s vascular mechanisms of action suggests, “caffeine has some cardiovascular properties and effects which could be considered beneficial,” (11) involving the association between decreased cerebral circulation and migrainous headache.
One of the main reasons we take pre-workout supplements: boost circulation. And so, naturally, the vasoconstriction of caffeine are typically viewed as a negative when it comes to performance enhancement. Whether we’re talking nootropic cognitive enhancers or bodybuilder pre-workout stacks, the goal is to boost blood flow, not inhibit it and caffeine free pre workouts are great for this.
- Study: in one 2009 study on the effects of daily caffeine use on cerebral blood flow, caffeine was shown to reduce cerebral blood flow by an average 27%, (12) which may significantly impact cognition and goes against the vasodilatory aims of pre-workout N.O. boosters.
Okay, So Is Caffeine A Legitimate Performance Enhancer?
Based on the study’s compiled above, the best performance enhancement potential of caffeine significantly depends upon how much caffeine you use, your personal caffeine tolerance, and when you take caffeine (i.e., how close to bedtime) so if sensitive, a caffeine free pre workout would be the way to go.
Of course, much of this is common sense.
But with a better understanding of how caffeine affects your mental and physical performance, you may make a smarter decision as to whether or not you want a caffeine free pre-workout supplement (or any stack for that matter).
An Optional Source Of Pre-Workout Caffeine: Transparent Labs PreSeries BULK Pre-Workout
Code GENIRON10 For 10% Off
Transparent Labs PreSeries BULK is backed by science with clinically effective dosages to increase muscle size and mass. This pre-workout is perfect for reducing fatigue, aiding in muscle growth, and boosting energy levels for better overall performance.
Transparent Labs BULK is the best bulking pre-workout for those looking to gain size and increase muscle mass. With 19 active ingredients and a transparent label, this supplement contains zero artificial sweeteners, flavors, or other additives for only the best in terms of your training and performance.
Top 5 Non-Caffeinated Pre-Workout Ingredients
Whether you’re looking at a caffeinated or caffeine free pre-workout supplement, some of the best pre-workout ingredients you need to look for include:
#1) Creatine
An organic compound highly concentrated in tissue, creatine works as precursor fuel for the natural production of ATP energy, a cleaner, more natural energy source than the stimulatory effects of caffeine. As a dietary supplement, it boosts exercise performance by (13,14):
- Replenishing exercise-depleted ATP energy
- Stimulating insulin-like growth factor 1 (IGF-1)
- Buffering muscular lactic acid build-up for better endurance
Best Pre-Workout Creatine: Creapure® pH10
- Creapure® pH10 is 99.5% pure creatine monohydrate
- pH-balanced to enhance bioavailability
- Clean and easy-to-absorb to reduce bloating and gastric distress
A well-known sports nutrition aid, namely for the skin-tingling sensation associated with it, Beta-Alanine replenishes levels of carnosine, a dipeptide molecule, in muscle tissue, namely fast-twitch fibers for increased strength and power during high-intensity exercise. Consistently loading and maintaining, carnosine benefits performance and recuperation by (15):
- Delaying onset fatigue and failure
- Enhancing overall strength and stamina
- Neutralizing exercise-induced free radicals
- Inhibiting advanced glycation end-products (AGEs)
- Buffering the impact of damaging acids
Best Pre-Workout Beta-Alanine: CarnoSyn®
- CarnoSyn® is the only beta-alanine with NDI (New Dietary Ingredient) status
- Generally Recognized as Safe (GRAS)
- Well-backed by years of clinical research
#3) L-Citrulline + L-Glutathione
L-Citrulline is an amino acid that, once absorbed, converts in the body to L-arginine, a nitric oxide (N.O.) booster that enhances muscular circulation, strength, and growth. In other words, L-citrulline works as your go-to pre-workout “muscle pump” booster and will help with mind-muscle connection.
Additionally, L-Glutathione is an antioxidant enzyme that, when paired with L-citrulline, benefits performance in a few ways. Combined, L-citrulline + L-glutathione work by (16):
- Promoting oxygen delivery to tissue
- Protecting muscle against oxidative stress
- Sustaining L-citrulline’s N.O.-boosting bioactivities
- Improving energy and anabolism
- Strengthening immunity against gym-related challenges
Best Pre-Workout L-Citrulline + L-Glutathione: Setria® Performance Blend
- Setria® Performance Blend is made by Kyowa Hakko Bio Co. Ltd., a world leader in supplement development
- Kyowa Quality® L-Citrulline is exceptionally clean and bioavailable
- Setria® is an advanced glutathione form that pairs well with Kyowa Quality® L-Citrulline
Formed by the harsh salty climes of the sea, maritime pine bark extract supplies proanthocyanidins, a potent class of antioxidants that:
- Promote endothelial production of nitric oxide (N.O.)
- Protect muscle tissue during intense training
- Boost long-term cognitive attentional performance
#5) Himalayan Pink Salt
Hydration is key to muscle growth, and, yet, when it comes to rehydration, we tend to overlook the importance of electrolytes to sustaining healthy H2O levels. As a natural source of electrolyte trace minerals, Himalayan Pink Salt is a smart choice for restoring sweat-depleted electrolytes when taken in a pre-workout context.
Conclusion
Frankly, our caffeine options are far from limited. If you want caffeine, you can get some. Odds are you’re enjoying a hot cup (or a cold can) of caffeine right now, as you read this, so looking for a caffeine free pre workout or one with caffeine is the choice you have to make.
However, what is hard to come by is a real-deal health and fitness supplement that genuinely supports athletic health and fitness. And with its all-natural, hard-hitting ergogenics packed in its caffeine-free pre-workout formula, Transparent Labs PreSeries Stim-Free Pre-Workout certainly fits the bill.
What’s more, Transparent Labs Stim-Free can be synergistically stacked with other top supplements in Transparent Labs Creatine HMB and Post-Workout.
The point isn’t to completely force you into a caffeine-free workout, but to grant you the option. Head to Transparent Labs to see more formulas with PreSeries Stim-Free Pre-Workout.
Generation Iron may receive commissions on purchases made through our links. See our disclosure page for more information.
Let us know what you think in the comments below. Also, be sure to follow Generation Iron on Facebook, Twitter, and Instagram.
*Images courtesy of Transparent Labs and Envato
References
[*]Cappelletti, S.; et al. (2015). “Caffeine: Cognitive and Physical Performance Enhancer or Psychoactive Drug?”.
[*]Evans J et al. Caffeine. [Updated 2020 Mar 22]. StatPearls. Treasure Island (FL): StatPearls Publishing; 2020 Jan.
[*]Heckman MA et al. Caffeine (1, 3, 7-trimethylxanthine) in Foods: A Comprehensive Review on Consumption, Functionality, Safety, and Regulatory Matters. J Food Sci. 2010 Apr; 75(3): R77-87.
[*]Papadelis C et al. Effects of Mental Workload and Caffeine on Catecholamines and Blood Pressure Compared to Performance Variations. Brain Cogn. 2003 Feb; 51(1): 143-54.
[*]Lovallo WR et al. Cortisol Responses to Mental Stress, Exercise, and Meals Following Caffeine Intake in Men and Women. Pharmacol Biochem Behav. 2006 Mar; 83(3): 441-7.
[*]Volkow ND et al. Caffeine increases striatal dopamine D2/D3receptor availability in the human brain. Transl Psychiatry. 2015 Apr; 5(4): e549.
[*]Souissi M et al. Effects of Morning Caffeine Ingestion on Mood States, Simple Reaction Time, and Short-Term maximal Performance on Elite Judoists. Asian J Sports Med. 2012 Sep; 3(3): 161-168.
[*]Bruce MS, Lader M. Caffeine Abstention in the Management of Anxiety Disorders. Psychol Med. 1989 Feb; 19(1): 211-4.
[*]Astrup A et al. Caffeine: A Double-Blind, Placebo-Controlled Study of Its Thermogenic, Metabolic, and Cardiovascular Effects in Healthy Volunteers. Am J Clin Nutr. 1990 May; 51(5): 759-67.
[*]Drake C et al. Caffeine Effects on Sleep Taken 0, 3, or 6 Hours before Going to Bed. J Clin Sleep Med. 2013 Nov 15; 9(11): 1195-1200.
[*]Echeverri D et al. Caffeine’s Vascular Mechanisms of Action. Int J Vasc Med. 2010; 2010: 834060.
[*]Addicott MA et al. The Effect of Daily Caffeine Use on Cerebral Blood Flow: How Much Caffeine Can We Tolerate?Hum Brain Mapp. 2009 Oct; 30(10): 3102-14.
[*]Cooper R et al. Creatine supplementation with specific view to exercise/sports performance: an update. J Int Soc Sports Nutr. 2012; 9: 33.
[*]Oliver JM et al. Oral Creatine Supplementation’s Decrease of Blood Lactate During Exhaustive, Incremental Cycling. Int J Sport Nutr Exerc Metab. 2013 Jun; 23(3): 252-8.
[*]Hobson RM et al. Effects of ?-alanine supplementation on exercise performance: a meta-analysis. Amino Acids. 2012 Jul; 43(1): 25-37.
[*]McKinley-Barnard S et al. Combined L-citrulline and Glutathione Supplementation Increases the Concentration of Markers Indicative of Nitric Oxide Synthesis. J Int Soc Sports Nutr. 2015 Jun 10; 12: 27.
Click here to view the article.
