Product Image

Kre-Alkalyn Hardcore

All American EFX Sports
4.6
★ ★ ★ ★ ★
(810 ratings)
Theobromine 100 mg
Caffeine 180 mg
Creatine 2000 mg
Product Image
Score71
A convenient creatine-and-stimulant capsule with strong energy potential, offset by modest creatine and a demanding multi-stimulant profile.
How scoring works
Quantity:120 Capsule(s) • (40 servings)
Goals:
Fitness
Metabolism Boost
Productivity Boost
Weight Loss
Energy
Mental Focus

Score 71

A convenient creatine-and-stimulant capsule with strong energy potential, offset by modest creatine and a demanding multi-stimulant profile.
How scoring works
$23.99($0.59 per serving)
iHerb
$ 23.99
Amazon
$ 23.99
Supplement City
$ 23.99
Report prices

Analysis

Kre-Alkalyn supplies the creatine component, while caffeine, theobromine, and theophylline create a broad stimulant profile. The combination may support workout drive and short-term performance, but it is not a complete muscle-gain formula.

Every active amount is listed, which is useful for assessing the formula. The creatine serving is below commonly used daily monohydrate amounts, and the combined stimulant compounds may feel stronger or last longer than caffeine alone.

Experienced users who want capsules and combined creatine-stimulant support may appreciate the convenience. People sensitive to stimulants or wanting straightforward creatine saturation should use separate, simpler products.

Who is it for
  • Experienced stimulant users seeking capsule pre-workout support
  • Adults who want creatine and stimulants together
Best for
  • Workout energy
  • Convenient pre-training capsules

Pros

  • All active amounts are disclosed
  • Includes creatine with three methylxanthines
  • Capsule format avoids flavored powder
  • Theobromine adds longer-lasting stimulation

Cons

  • Creatine amount is modest for daily use
  • Combined stimulant burden may be intense
  • Green coffee extract lacks marker standardization
  • Three capsules per serving

Warnings

  • Caffeine, theobromine, and theophylline may combine to cause palpitations or insomnia
  • Theophylline has a narrower tolerance margin than caffeine
  • Avoid other stimulant products and limit additional coffee
  • People using theophylline or interacting medicines should not combine them without clinician guidance

Nutrient quality

66 High impact

Buffered creatine and a meaningful caffeine dose provide a practical performance core. Multiple stimulants and small extras reduce balance and increase tolerability concerns.

.

Ingredient transparency

79 High impact

Most active doses are visible without a proprietary blend. Green-coffee caffeine yield, complete directions, inactive ingredients, and branded extract details remain unclear.

.

Customer satisfaction

68 High impact

The supplied average is strong and supported by substantial volume. No review themes were provided, so consistency and purpose-specific experience cannot be assessed.

.

Value for money

67 High impact

Useful creatine and stimulant amounts support fair performance value. Several small extras and a crowded stimulant profile reduce quality-adjusted competitiveness.

.
Report analysis

Goals

Fitness
Fitness
Impact
Highest effect
A+ Goal FitA Strength of SupportB+ CoverageC Formula Quality
Creatine · 2000 mgCaffeine · 180 mg

Buffered creatine and caffeine directly support repeated high-intensity effort, strength work, and acute workout drive. Their disclosed amounts are meaningful, while creatine and caffeine both have strong human performance evidence.

The stimulant stack also includes green coffee, theobromine, and theophylline, which may increase intensity without improving dose control. Combining these stimulants with other caffeine can cause jitteriness, a rapid heartbeat, or sleep disruption, especially in sensitive users.

Study evidence
Caffeine Supportive 255 studies
Creatine Supportive 143 studies
Metabolism Boost
Metabolism Boost
Impact
Highest effect
A+ Goal FitA- Strength of SupportB+ CoverageB Formula Quality
Creatine · 2000 mgCaffeine · 180 mg

Caffeine, green coffee, theobromine, and theophylline directly target alertness and thermogenesis. Human evidence for caffeine-related energy expenditure is strong, while raspberry ketones have weak human support.

Caffeine at 180 mg is substantial, with additional methylxanthines adding stimulant exposure. Most amounts and anhydrous caffeine are clear, while green-coffee marker standardization is absent. Combined caffeine, theobromine, and theophylline may cause insomnia, anxiety, rapid heartbeat, or elevated blood pressure.

Study evidence
Caffeine Disputed 40 studies
Creatine Supportive 21 studies
Productivity Boost
Productivity Boost
Impact
Highest effect
A- Goal FitA- Strength of SupportB- CoverageC+ Formula Quality
Creatine · 2000 mgCaffeine · 180 mg

A 180 mg caffeine dose provides clear short-term alertness, while creatine may support performance during demanding work. Green coffee, theobromine, and theophylline add more stimulation rather than a calming counterbalance.

All active amounts are disclosed, and the caffeine dose is practical for many experienced users. Combining several methylxanthine stimulants may increase jitters, palpitations, anxiety, or sleep disruption, especially with other caffeine sources.

Study evidence
Caffeine Supportive 108 studies
Creatine Supportive 16 studies
Weight Loss
Weight Loss
Impact
Highest effect
A- Goal FitB+ Strength of SupportB+ CoverageB- Formula Quality
Creatine · 2000 mgCaffeine · 180 mg

Caffeine can support energy expenditure and training output, while creatine may help preserve strength and lean mass during a calorie deficit. Green coffee, theobromine, and theophylline add further stimulation.

The stimulant stack may cause jitteriness, rapid heartbeat, or sleep disruption, especially when combined with other caffeine sources. Raspberry ketones are only 25 mg and lack convincing human weight-loss evidence, making them mostly label decoration.

Study evidence
Caffeine Disputed 14 studies
Creatine No effect 27 studies
Energy
Energy
Impact
High effect
A Goal FitA- Strength of SupportB CoverageD- Formula Quality
Caffeine · 180 mgCreatine · 2000 mg

Caffeine provides reliable acute alertness, while creatine can support repeated high-intensity performance. The 180 mg caffeine amount is functional, but the 2,000 mg creatine amount is below the usual daily maintenance range.

Caffeine, green coffee, theobromine, and theophylline create a crowded stimulant stack that may cause jitteriness, nausea, headache, rapid heartbeat, or sleep disruption. Raspberry ketones add little credible energy value.

Study evidence
Caffeine Supportive 68 studies
Creatine Supportive 49 studies
Theobromine Adverse 1 study
Mental Focus
Mental Focus
Impact
High effect
B+ Goal FitA- Strength of SupportB CoverageC- Formula Quality
Creatine · 2000 mgCaffeine · 180 mg

Caffeine, theobromine, and theophylline provide pronounced stimulation, while creatine may support cellular energy. The formula can increase alertness but relies heavily on overlapping stimulants.

Exact active amounts make the serving easy to assess, and the main doses are meaningful. Combining 180 mg caffeine with theobromine, theophylline, and green coffee may increase jitteriness, nausea, rapid heartbeat, or sleep disruption.

Study evidence
Caffeine Supportive 128 studies
Creatine Supportive 13 studies
Muscle Gain
Muscle Gain
Impact
Moderate effect
B- Goal FitC- Strength of SupportC- CoverageD+ Formula Quality
Creatine · 2000 mgCaffeine · 180 mg

Creatine provides a direct strength and power mechanism, giving the product meaningful relevance to muscle gain. The two-gram Kre-Alkalyn amount is below the usual daily creatine amount, while caffeine adds acute training drive rather than long-term hypertrophy by itself.

The creatine form and main stimulant amounts are disclosed, but buffered creatine has less evidence than monohydrate. Caffeine, theobromine, and theophylline can combine to raise heart rate or impair sleep in stimulant-sensitive users.

Study evidence
Caffeine Supportive 31 studies
Creatine Supportive 136 studies

Ingredients

IngredientAmount per serving
Kre-Alkalyn
2000 mg
Caffeine Anhydrous
180 mg
Green Coffee Extract
120 mg
Theobromine
100 mg
Razberi-K
25 mg
Adults 18–50 Women
Report overview
Theobromine · 100 mg OverallScore94
A- Active Ingredient Quality & BioavailabilityA+ Dose, Safety & Label TransparencyA+ Value

The purified standalone theobromine dose fits the collection's effective range and is clearly disclosed. Its serving cost is very low for the amount supplied. Combining theobromine with caffeine and theophylline may increase stimulant-related effects such as nausea, headache, jitteriness, or a rapid heartbeat in sensitive users.

View ingredientView products
Caffeine · 180 mg OverallScore82
B Active Ingredient Quality & BioavailabilityA+ Dose, Safety & Label TransparencyC Value

Caffeine anhydrous provides a clearly stated dose suited to acute focus and performance. The formula uses immediate-release caffeine rather than a staged delivery system, so its effects may feel less even over time. Caffeine combined with theobromine and theophylline can increase jitteriness or heart-rate effects, so stimulant-sensitive users should avoid stacking it with other caffeine.

View ingredientView products
Creatine · 2000 mg OverallScore78
B- Active Ingredient Quality & BioavailabilityB+ Dose, Safety & Label TransparencyB+ Value

The buffered creatine dose is well aligned with the usual effective range for concentrated forms. Capsule delivery is convenient, but the lack of a named independent certification leaves purity less certain. A strong stimulant blend of caffeine, theobromine, theophylline, and green coffee extract may cause jitteriness, sleep disruption, or a rapid heartbeat, especially for people sensitive to stimulants or combining it with other caffeine sources.

View ingredientView products
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Report alternatives

Sources

Published studies used for the product analysis and the top-ranked studies for each ingredient and goal.

  1. Effect of caffeine ingestion on cycling performance: a systematic review and meta-analysis.
    Wu J; Xu K; Yin M; Ding X; Wang T; Zhang Q; Wu X; Xiao N · Frontiers in nutrition · 2026
    Meta-analysis226 participants20 studies pooledFitness forCaffeine
  2. Acute Effects of Caffeine Supplementation on Physical Performance, Physiological Responses, Perceived Exertion, and Technical-Tactical Skills in Combat Sports: A Systematic Review and Meta-Analysis.
    Delleli S; Ouergui I; Messaoudi H; Trabelsi K; Ammar A; Glenn JM; Chtourou H · Nutrients · 2022
    Meta-analysis26 studies pooledFitness forCaffeine
  3. Creatine in combination with resistance training and improvement in muscle strength: evaluation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006.
    EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) · EFSA journal. European Food Safety Authority · 2026
    Guideline / consensusFitness forCreatine
  4. Creatine Monohydrate Supplementation Does Not Augment Fitness, Performance, or Body Composition Adaptations in Response to Four Weeks of High-Intensity Interval Training in Young Females.
    Forbes SC; Sletten N; Durrer C; Myette-Côté É; Candow D; Little JP · International journal of sport nutrition and exercise metabolism · 2017
    Randomized trial17 participantsFitness forCreatine
  5. Effects of modafinil and caffeine on night-time vigilance of air force crewmembers: A randomized controlled trial.
    Wingelaar-Jagt YQ; Bottenheft C; Riedel WJ; Ramaekers JG · Journal of psychopharmacology (Oxford, England) · 2023
    Randomized trial32 participantsMental Focus forCaffeine
  6. Caffeinated Coffee and Tea Consumption, Genetic Variation and Cognitive Function in the UK Biobank.
    Cornelis MC; Weintraub S; Morris MC · The Journal of nutrition · 2020
    Cross-sectional study445,786 participantsMental Focus forCaffeine
  7. Wake up and smell the coffee: caffeine supplementation and exercise performance-an umbrella review of 21 published meta-analyses.
    Grgic J; Grgic I; Pickering C; Schoenfeld BJ; Bishop DJ; Pedisic Z · British journal of sports medicine · 2020
    Systematic review21 studies pooledMuscle Gain forCaffeine
  8. Caffeine Optimizes HIIT Benefits on Obesity-associated Metabolic Adversity in Women.
    Alkhatib A; Hsieh MJ; Kuo CH; Hou CW · Medicine and science in sports and exercise · 2021
    Randomized trial24 participantsMuscle Gain forCaffeine
  9. Effects of Creatine Supplementation and Resistance Training on Muscle Strength Gains in Adults <50 Years of Age: A Systematic Review and Meta-Analysis.
    Wang Z; Qiu B; Li R; Han Y; Petersen C; Liu S; Zhang Y; Liu C; Candow DG; Del Coso J · Nutrients · 2024
    Meta-analysis509 participants23 studies pooledMuscle Gain forCreatine
  10. The Effects of Creatine Supplementation Combined with Resistance Training on Regional Measures of Muscle Hypertrophy: A Systematic Review with Meta-Analysis.
    Burke R; Piñero A; Coleman M; Mohan A; Sapuppo M; Augustin F; Aragon AA; Candow DG; Forbes SC; Swinton P; Schoenfeld BJ · Nutrients · 2023
    Meta-analysis10 studies pooledMuscle Gain forCreatine
  11. Creatine supplementation does not add to resistance training effects in prostate cancer patients under androgen deprivation therapy: A double-blind randomized trial.
    Fairman CM; Kendall KL; Newton RU; Hart NH; Taaffe DR; Lopez P; Chee R; Tang CI; Galvão DA · Journal of science and medicine in sport · 2025
    Randomized trial30 participantsMuscle Gain forCreatine
  12. Cognitive and mood improvements of caffeine in habitual consumers and habitual non-consumers of caffeine.
    Haskell CF; Kennedy DO; Wesnes KA; Scholey AB · Psychopharmacology · 2005
    Randomized trial48 participantsEnergy forCaffeine
  13. Caffeine-containing energy drink improves physical performance of elite rugby players during a simulated match.
    Del Coso J; Ramírez JA; Muñoz G; Portillo J; Gonzalez-Millán C; Muñoz V; Barbero-Álvarez JC; Muñoz-Guerra J · Applied physiology, nutrition, and metabolism = Physiologie appliquee, nutrition et metabolisme · 2016
    Randomized trial26 participantsEnergy forCaffeine
  14. Differential cognitive effects of energy drink ingredients: caffeine, taurine, and glucose.
    Giles GE; Mahoney CR; Brunyé TT; Gardony AL; Taylor HA; Kanarek RB · Pharmacology, biochemistry, and behavior · 2013
    Randomized trial48 participantsEnergy forCaffeine
  15. Does Single or Combined Caffeine and Taurine Supplementation Improve Athletic and Cognitive Performance without Affecting Fatigue Level in Elite Boxers? A Double-Blind, Placebo-Controlled Study.
    Ozan M; Buzdagli Y; Eyipinar CD; Baygutalp NK; Yüce N; Oget F; Kan E; Baygutalp F · Nutrients · 2022
    Randomized trial20 participantsEnergy forCaffeine
  16. Trait Energy and Fatigue Modify the Effects of Caffeine on Mood, Cognitive and Fine-Motor Task Performance: A Post-Hoc Study.
    Fuller DT; Smith ML; Boolani A · Nutrients · 2021
    Randomized trialEnergy forCaffeine
  17. Synergistic effects of creatine, carbs, protein on repeated sprint performance.
    Wang Y; Wei H; Cheng X; Chen Z · Scientific reports · 2026
    Randomized trial60 participantsEnergy forCreatine
  18. The Effects of Creatine Monohydrate Supplementation on Recovery from Eccentric Exercise-Induced Muscle Damage: A Double-Blind, Randomized, Placebo-Controlled Trial Considering Sex and Age Differences.
    Yamaguchi S; Inami T; Nishioka T; Morito A; Ishiyama K; Murayama M · Nutrients · 2025
    Randomized trial40 participantsEnergy forCreatine
  19. The Effect of Prior Creatine Intake for 28 Days on Accelerated Recovery from Exercise-Induced Muscle Damage: A Double-Blind, Randomized, Placebo-Controlled Trial.
    Yamaguchi S; Inami T; Ishida H; Morito A; Yamada S; Nagata N; Murayama M · Nutrients · 2024
    Randomized trial20 participantsEnergy forCreatine
  20. Creatine supplementation attenuates the rate of fatigue development during intermittent isometric exercise performed above end-test torque.
    Abdalla LHP; Broxterman RM; Greco CC; Denadai BS · Experimental physiology · 2021
    Randomized trial16 participantsEnergy forCreatine
  21. The effect of continuous low dose creatine supplementation on force, power, and total work.
    Burke DG; Silver S; Holt LE; Smith Palmer T; Culligan CJ; Chilibeck PD · International journal of sport nutrition and exercise metabolism · 2000
    Randomized trial41 participantsEnergy forCreatine
  22. Sleep symptoms associated with intake of specific dietary nutrients.
    Grandner MA; Jackson N; Gerstner JR; Knutson KL · Journal of sleep research · 2014
    Cross-sectional study4,552 participantsEnergy forTheobromine
  23. Effects of Caffeine Intake on Endurance Running Performance and Time to Exhaustion: A Systematic Review and Meta-Analysis.
    Wang Z; Qiu B; Gao J; Del Coso J · Nutrients · 2023
    Meta-analysis254 participants21 studies pooledFitness forCaffeine
  24. Acute Effects of Caffeine Supplementation on Movement Velocity in Resistance Exercise: A Systematic Review and Meta-analysis.
    Raya-González J; Rendo-Urteaga T; Domínguez R; Castillo D; Rodríguez-Fernández A; Grgic J · Sports medicine (Auckland, N.Z.) · 2021
    Meta-analysis12 studies pooledFitness forCaffeine
  25. Sex Differences in the Ergogenic Response of Acute Caffeine Intake on Muscular Strength, Power and Endurance Performance in Resistance-Trained Individuals: A Randomized Controlled Trial.
    Montalvo-Alonso JJ; Ferragut C; Del Val-Manzano M; Valadés D; Roberts J; Pérez-López A · Nutrients · 2024
    Randomized trial76 participantsFitness forCaffeine
  26. Can I Have My Coffee and Drink It? A Systematic Review and Meta-analysis to Determine Whether Habitual Caffeine Consumption Affects the Ergogenic Effect of Caffeine.
    Carvalho A; Marticorena FM; Grecco BH; Barreto G; Saunders B · Sports medicine (Auckland, N.Z.) · 2022
    Meta-analysis60 studies pooledFitness forCaffeine
  27. Effect of creatine and weight training on muscle creatine and performance in vegetarians.
    Burke DG; Chilibeck PD; Parise G; Candow DG; Mahoney D; Tarnopolsky M · Medicine and science in sports and exercise · 2004
    Randomized trial42 participantsFitness forCreatine
  28. Long-term creatine intake is beneficial to muscle performance during resistance training.
    Vandenberghe K; Goris M; Van Hecke P; Van Leemputte M; Vangerven L; Hespel P · Journal of applied physiology (Bethesda, Md. : 1985) · 1998
    Randomized trial19 participantsFitness forCreatine
  29. Effects of Combined Versus Single Supplementation of Creatine, Beta-Alanine, and L-Citrulline During Short Sprint Interval Training on Basketball Players' Performance: A Double-Blind Randomized Placebo-Controlled Trial.
    Li M; Sheykhlouvand M · International journal of sports physiology and performance · 2025
    Randomized trial48 participantsFitness forCreatine
  30. The Additive Effects of Creatine Supplementation and Exercise Training in an Aging Population: A Systematic Review of Randomized Controlled Trials.
    Stares A; Bains M · Journal of geriatric physical therapy (2001) · 2021
    Systematic review17 studies pooledFitness forCreatine
  31. Acute effects of caffeine on attention: a comparison of non-consumers and withdrawn consumers.
    Smith AP; Christopher G; Sutherland D · Journal of psychopharmacology (Oxford, England) · 2013
    Randomized trial70 participantsMental Focus forCaffeine
  32. Performance and alertness effects of caffeine, dextroamphetamine, and modafinil during sleep deprivation.
    Wesensten NJ; Killgore WD; Balkin TJ · Journal of sleep research · 2006
    Randomized trial48 participantsMental Focus forCaffeine
  33. Effects of caffeine on mood and performance: a study of realistic consumption.
    Brice CF; Smith AP · Psychopharmacology · 2003
    Clinical trial24 participantsMental Focus forCaffeine
  34. Effects of caffeine or diphenhydramine on visual vigilance.
    Fine BJ; Kobrick JL; Lieberman HR; Marlowe B; Riley RH; Tharion WJ · Psychopharmacology · 1995
    Randomized trial24 participantsMental Focus forCaffeine
  35. The Effects of 8-Week Creatine Hydrochloride and Creatine Ethyl Ester Supplementation on Cognition, Clinical Outcomes, and Brain Creatine Levels in Perimenopausal and Menopausal Women (CONCRET-MENOPA): A Randomized Controlled Trial.
    Korovljev D; Ostojic J; Panic J; Ranisavljev M; Todorovic N; Nedeljkovic D; Kuzmanovic J; Vranes M; Stajer V; Ostojic SM · Journal of the American Nutrition Association · 2026
    Randomized trial36 participantsMental Focus forCreatine
  36. Creatine and Cognition in Aging: A Systematic Review of Evidence in Older Adults.
    Marshall S; Kitzan A; Wright J; Bocicariu L; Nagamatsu LS · Nutrition reviews · 2026
    Systematic review1,542 participants6 studies pooledMental Focus forCreatine
  37. Effect of creatine supplementation and sleep deprivation, with mild exercise, on cognitive and psychomotor performance, mood state, and plasma concentrations of catecholamines and cortisol.
    McMorris T; Harris RC; Swain J; Corbett J; Collard K; Dyson RJ; Dye L; Hodgson C; Draper N · Psychopharmacology · 2006
    Clinical trial19 participantsMental Focus forCreatine
  38. Six-Week Supplementation with Creatine in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): A Magnetic Resonance Spectroscopy Feasibility Study at 3 Tesla.
    Godlewska BR; Sylvester AL; Emir UE; Sharpley AL; Clarke WT; Martens MAG; Cowen PJ · Nutrients · 2024
    Single-arm trial14 participantsMental Focus forCreatine
  39. The effects of creatine supplementation on cognitive function in adults: a systematic review and meta-analysis.
    Xu C; Bi S; Zhang W; Luo L · Frontiers in nutrition · 2026
    Meta-analysis492 participants16 studies pooledMental Focus forCreatine
  40. A Randomized Study to Examine the Ability of a Caffeine-Based Energy Drink to Impact Energy Expenditure, Fat Oxidation, and Cognitive Performance.
    Krieger J; Schrautemeier A; Hagele A; Gaige C; Mennemeyer O; Tolbert S; Iannotti J; Kerksick C; Noonan C; Mumford P · Nutrients · 2025
    Randomized trial60 participantsMetabolism Boost forCaffeine
  41. Oolong tea increases metabolic rate and fat oxidation in men.
    Rumpler W; Seale J; Clevidence B; Judd J; Wiley E; Yamamoto S; Komatsu T; Sawaki T; Ishikura Y; Hosoda K · The Journal of nutrition · 2001
    Randomized trial12 participantsMetabolism Boost forCaffeine
  42. Effect of caffeine intake on fat oxidation rate during exercise: is there a dose-response effect?
    Gutiérrez-Hellín J; Aguilar-Navarro M; Ruiz-Moreno C; Muñoz A; Varillas-Delgado D; Amaro-Gahete FJ; Del Coso J · European journal of nutrition · 2023
    Randomized trial18 participantsMetabolism Boost forCaffeine
  43. Comparison of changes in energy expenditure and body temperatures after caffeine consumption.
    Koot P; Deurenberg P · Annals of nutrition & metabolism · 1995
    Randomized trial12 participantsMetabolism Boost forCaffeine
  44. Caffeine Increases Work Done above Critical Power, but Not Anaerobic Work.
    Silveira R; Andrade-Souza VA; Arcoverde L; Tomazini F; Sansonio A; Bishop DJ; Bertuzzi R; Lima-Silva AE · Medicine and science in sports and exercise · 2018
    Randomized trial9 participantsMetabolism Boost forCaffeine
  45. Creatine target engagement with brain bioenergetics: a dose-ranging phosphorus-31 magnetic resonance spectroscopy study of adolescent females with SSRI-resistant depression.
    Kondo DG; Forrest LN; Shi X; Sung YH; Hellem TL; Huber RS; Renshaw PF · Amino acids · 2017
    Randomized trialMetabolism Boost forCreatine
  46. Creatine supplementation and glycemic control: a systematic review.
    Pinto CL; Botelho PB; Pimentel GD; Campos-Ferraz PL; Mota JF · Amino acids · 2017
    Systematic reviewMetabolism Boost forCreatine
  47. The effect of dietary creatine supplementation on skeletal muscle metabolism in congestive heart failure.
    Andrews R; Greenhaff P; Curtis S; Perry A; Cowley AJ · European heart journal · 1998
    Clinical trialMetabolism Boost forCreatine
  48. A comprehensive review of the physiology and evidence base to guide the use of ergogenic and medical supplements for enhanced cycling performance.
    Rowland A; Edwards S; Prieto-Bellver G; Menz B; Rowland A; Cornelisse E; Karapetis CS; Wallen MP; Hopkins AM · Journal of the International Society of Sports Nutrition · 2026
    Narrative reviewMetabolism Boost forCreatine
  49. Creatine Supplementation Beyond Athletics: Benefits of Different Types of Creatine for Women, Vegans, and Clinical Populations-A Narrative Review.
    Gutiérrez-Hellín J; Del Coso J; Franco-Andrés A; Gamonales JM; Espada MC; González-García J; López-Moreno M; Varillas-Delgado D · Nutrients · 2025
    Narrative reviewMetabolism Boost forCreatine
  50. Effects of Acute Ingestion of Caffeine Capsules on Muscle Strength and Muscle Endurance: A Systematic Review and Meta-Analysis.
    Wu W; Chen Z; Zhou H; Wang L; Li X; Lv Y; Sun T; Yu L · Nutrients · 2024
    Meta-analysis14 studies pooledMuscle Gain forCaffeine
  51. Acute caffeine intake improves muscular strength, power, and endurance performance, reversing the time-of-day effect regardless of muscle activation level in resistance-trained males: a randomized controlled trial.
    Montalvo-Alonso JJ; Del Val-Manzano M; Cerezo-Telléz E; Ferragut C; Valadés D; Rodríguez-Falces J; Pérez-López A · European journal of applied physiology · 2025
    Randomized trial13 participantsMuscle Gain forCaffeine
  52. Effects of caffeine intake on muscle strength and power: a systematic review and meta-analysis.
    Grgic J; Trexler ET; Lazinica B; Pedisic Z · Journal of the International Society of Sports Nutrition · 2018
    Meta-analysis20 studies pooledMuscle Gain forCaffeine
  53. Caffeine increases strength and power performance in resistance-trained females during early follicular phase.
    Norum M; Risvang LC; Bjørnsen T; Dimitriou L; Rønning PO; Bjørgen M; Raastad T · Scandinavian journal of medicine & science in sports · 2021
    Randomized trial15 participantsMuscle Gain forCaffeine
  54. The Effect of Creatine Supplementation on Resistance Training-Based Changes to Body Composition: A Systematic Review and Meta-analysis.
    Desai I; Wewege MA; Jones MD; Clifford BK; Pandit A; Kaakoush NO; Simar D; Hagstrom AD · Journal of strength and conditioning research · 2025
    Meta-analysis362 participants12 studies pooledMuscle Gain Weight Loss forCreatine
  55. Comparative Effects of Dietary Protein, Creatine, and Omega-3 Supplementation on Muscle Strength, Endurance, and Recovery in Trained Athletes: A Systematic Review and Network Meta-Analysis.
    Wang Z; Qin G; Kim BM · Nutrients · 2026
    Meta-analysis1,211 participants35 studies pooledMuscle Gain forCreatine
  56. Effect of creatine supplementation during resistance training on lean tissue mass and muscular strength in older adults: a meta-analysis.
    Chilibeck PD; Kaviani M; Candow DG; Zello GA · Open access journal of sports medicine · 2020
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