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Frequently Asked Questions about Power Output
Are energy drinks bad for you?
Case studies have linked energy drinks to adverse effects, especially on the cardiovascular system, but the overall risk of something bad happening is low and context-dependent.
Human Effect Matrix
The Human Effect Matrix looks at human studies (it excludes animal and in vitro studies) to tell you what supplements affect power output
|Grade||Level of Evidence [show legend]|
|Robust research conducted with repeated double-blind clinical trials|
|Multiple studies where at least two are double-blind and placebo controlled|
|Single double-blind study or multiple cohort studies|
|Uncontrolled or observational studies only|
Level of Evidence
? The amount of high quality evidence. The more evidence, the more we can trust the results.
Magnitude of effect
? The direction and size of the supplement's impact on each outcome. Some supplements can have an increasing effect, others have a decreasing effect, and others have no effect.
Consistency of research results
? Scientific research does not always agree. HIGH or VERY HIGH means that most of the scientific research agrees.
|Strong||Very High See all 66 studies|
|-||Moderate See all 12 studies|
|-||Moderate See all 28 studies|
- Wiggers D, et al. Use and Perceptions of Caffeinated Energy Drinks and Energy Shots in Canada. Am J Prev Med. (2017)
- Stephens MB, et al. Energy drink and energy shot use in the military. Nutr Rev. (2014)
- Malinauskas BM, et al. A survey of energy drink consumption patterns among college students. Nutr J. (2007)
- Utter J, et al. Energy drink consumption among New Zealand adolescents: Associations with mental health, health risk behaviours and body size. J Paediatr Child Health. (2017)
- Hammond D, Reid JL. Exposure and perceptions of marketing for caffeinated energy drinks among young Canadians. Public Health Nutr. (2018)
- Emond JA, Sargent JD, Gilbert-Diamond D. Patterns of energy drink advertising over US television networks. J Nutr Educ Behav. (2015)
- Francis J, et al. Informing Intervention Strategies to Reduce Energy Drink Consumption in Young People: Findings From Qualitative Research. J Nutr Educ Behav. (2017)
- Hammond D, Reid JL, Zukowski S. Adverse effects of caffeinated energy drinks among youth and young adults in Canada: a Web-based survey. CMAJ Open. (2018)
- Scholey AB, Kennedy DO. Cognitive and physiological effects of an "energy drink": an evaluation of the whole drink and of glucose, caffeine and herbal flavouring fractions. Psychopharmacology (Berl). (2004)
- Giles GE, et al. Differential cognitive effects of energy drink ingredients: caffeine, taurine, and glucose. Pharmacol Biochem Behav. (2012)
- Temple JL, et al. The Safety of Ingested Caffeine: A Comprehensive Review. Front Psychiatry. (2017)
- Faber MS, Jetter A, Fuhr U. Assessment of CYP1A2 activity in clinical practice: why, how, and when?. Basic Clin Pharmacol Toxicol. (2005)
- Rétey JV, et al. A genetic variation in the adenosine A2A receptor gene (ADORA2A) contributes to individual sensitivity to caffeine effects on sleep. Clin Pharmacol Ther. (2007)
- Alsene K, et al. Association between A2a receptor gene polymorphisms and caffeine-induced anxiety. Neuropsychopharmacology. (2003)
- Malik VS, Schulze MB, Hu FB. Intake of sugar-sweetened beverages and weight gain: a systematic review. Am J Clin Nutr. (2006)
- Bray GA, Popkin BM. Dietary sugar and body weight: have we reached a crisis in the epidemic of obesity and diabetes?: health be damned! Pour on the sugar. Diabetes Care. (2014)
- Seifert SM, et al. An analysis of energy-drink toxicity in the National Poison Data System. Clin Toxicol (Phila). (2013)
- Miles-Chan JL, et al. The blood pressure-elevating effect of Red Bull energy drink is mimicked by caffeine but through different hemodynamic pathways. Physiol Rep. (2015)
- Grasser EK, et al. Energy Drinks and Their Impact on the Cardiovascular System: Potential Mechanisms. Adv Nutr. (2016)
- Di Rocco JR, et al. Atrial fibrillation in healthy adolescents after highly caffeinated beverage consumption: two case reports. J Med Case Rep. (2011)
- Shen J, et al. Dietary factors and incident atrial fibrillation: the Framingham Heart Study. Am J Clin Nutr. (2011)
- Hanan Israelit S, Strizevsky A, Raviv B. ST elevation myocardial infarction in a young patientafter ingestion of caffeinated energy drink and ecstasy. World J Emerg Med. (2012)
- Kaoukis A, et al. Reverse Takotsubo cardiomyopathy associated with the consumption of an energy drink. Circulation. (2012)
- Rottlaender D, et al. Cardiac arrest due to long QT syndrome associated with excessive consumption of energy drinks. Int J Cardiol. (2012)
- Berger AJ, Alford K. Cardiac arrest in a young man following excess consumption of caffeinated "energy drinks". Med J Aust. (2009)
- Benjo AM, et al. Left main coronary artery acute thrombosis related to energy drink intake. Circulation. (2012)
- Jonjev ZS, Bala G. High-energy drinks may provoke aortic dissection. Coll Antropol. (2013)
- Gaskins AJ, et al. Pre-pregnancy caffeine and caffeinated beverage intake and risk of spontaneous abortion. Eur J Nutr. (2016)
- Silva CG, et al. Adenosine receptor antagonists including caffeine alter fetal brain development in mice. Sci Transl Med. (2013)
- Knutti R, Rothweiler H, Schlatter C. The effect of pregnancy on the pharmacokinetics of caffeine. Arch Toxicol Suppl. (1982)
- Ruxton CH. The suitability of caffeinated drinks for children: a systematic review of randomised controlled trials, observational studies and expert panel guidelines. J Hum Nutr Diet. (2014)
- Alford C, Cox H, Wescott R. The effects of red bull energy drink on human performance and mood. Amino Acids. (2001)
- Howard MA, Marczinski CA. Acute effects of a glucose energy drink on behavioral control. Exp Clin Psychopharmacol. (2010)
- van den Eynde F, et al. The effects of energy drinks on cognitive performance. Tijdschr Psychiatr. (2008)
- Roehrs T, Roth T. Caffeine: sleep and daytime sleepiness. Sleep Med Rev. (2008)
- Souza DB, et al. Acute effects of caffeine-containing energy drinks on physical performance: a systematic review and meta-analysis. Eur J Nutr. (2017)