While they may sometimes get a bad rap, the best energy drinks have plenty of positives. They offer an alternative stimulant for those who don’t enjoy the taste of coffee – or its high price – when out and about. Energy drinks also tend to come in a variety of tasty and interesting flavours, offer a significant caffeine boost that even some stronger coffees fail to match and are easily portable and storable for long periods of time. Another interesting thing about energy drinks is the tight-knit communities and fan-followings they sometimes develop due to their fun, maximalist aesthetics and sponsorship of extreme sports and up-and-coming music scenes.

It is unlikely that a toxic amount of caffeine can be consumed from caffeinated beverages alone. 8 However, large doses of caffeine are dangerous and there have been deaths from people consuming caffeine in tablet or powder form. 9 It may also increase blood adrenaline levels and increase brain activity of the neurotransmitters dopamine and norepinephrine ( 3). Research has shown that while caffeine remains in your system for an average of five hours, the time period may range from one and a half hours to nine hours, depending on the individual ( 17).

The metabolism of caffeine is reduced in pregnancy, especially in the third trimester, and the half-life of caffeine during pregnancy can be increased up to 15 hours (as compared to 2.5 to 4.5 hours in non-pregnant adults). [79] Current evidence regarding the effects of caffeine on pregnancy and for breastfeeding are inconclusive. [28] There is limited primary and secondary advice for, or against, caffeine use during pregnancy and its effects on the fetus or newborn. [28] Coffee is a brewed beverage prepared from coffee beans, which are a natural source of caffeine ( 1, 2, 3). For example, an energy shot may contain up to 350 mg of caffeine, while some energy drinks provide as much as a whopping 505 mg per can ( 16). Commercially prepared coffee- flavoured milk beverages are popular in Australia. [236] Examples include Oak's Ice Coffee and Farmers Union Iced Coffee. The amount of caffeine in these beverages can vary widely. Caffeine concentrations can differ significantly from the manufacturer's claims. [226]

A study found that a second cup of coffee produced no further benefits unless it was consumed at least 8 hours after the first cup ( 9). Grosso G, et al. Coffee, caffeine, and health outcomes: An umbrella review. Annual Review of Nutrition. 2019; doi:10.1146/annurev-nutr-071816-064941. This is more likely to cause side effects, as a full key down/key up is generated. It's included for compatibility with older systems which might need thisCaffeine is used for both prevention [34] and treatment [35] of bronchopulmonary dysplasia in premature infants. It may improve weight gain during therapy [36] and reduce the incidence of cerebral palsy as well as reduce language and cognitive delay. [37] [38] On the other hand, subtle long-term side effects are possible. [39] Consumption of 1–1.5 grams (1,000–1,500mg) per day is associated with a condition known as caffeinism. [138] Caffeinism usually combines caffeine dependency with a wide range of unpleasant symptoms including nervousness, irritability, restlessness, insomnia, headaches, and palpitations after caffeine use. [139] You may have noticed that you need to urinate frequently when you drink more coffee or tea than usual. Instead of F15, the shift key is used. This solves some of the issues with the above apps, but may cause the shift key to become "unpressed" sometimes

In healthy children, moderate caffeine intake under 400mg produces effects that are "modest and typically innocuous". [74] [75] As early as six months old, infants can metabolize caffeine at the same rate as that of adults. [76] Higher doses of caffeine (>400mg) can cause physiological, psychological and behavioral harm, particularly for children with psychiatric or cardiac conditions. [74] There is no evidence that coffee stunts a child's growth. [77] The American Academy of Pediatrics recommends that caffeine consumption is not appropriate for children and adolescents and should be avoided. [78] This recommendation is based on a clinical report released by American Academy of Pediatrics in 2011 with a review of 45 publications from 1994 to 2011 and includes inputs from various stakeholders (Pediatricians, Committee on nutrition, Canadian Pediatric Society, Centers for Disease Control & Prevention, Food and Drug Administration, Sports Medicine & Fitness committee, National Federations of High School Associations). [78] For children age 12 and under, Health Canada recommends a maximum daily caffeine intake of no more than 2.5 milligrams per kilogram of body weight. Based on average body weights of children, this translates to the following age-based intake limits: [72] Age range On average, an 8-ounce (240-mL) cup of coffee contains about 100 mg of caffeine. At this level, 4 cups of coffee per day will keep you within the safe limit of 400 mg of caffeine for healthy adults. The amount of caffeine in seemingly similar high-street coffees can vary significantly. Photograph: Wera Rodsawang/Getty Images Additionally, modest doses have been shown to cause rapid breathing and increase stress levels when consumed in one sitting ( 11, 12). Caffeine improves muscular strength and power, [66] and may enhance muscular endurance. [67] Caffeine also enhances performance on anaerobic tests. [68] Caffeine consumption before constant load exercise is associated with reduced perceived exertion. While this effect is not present during exercise-to-exhaustion exercise, performance is significantly enhanced. This is congruent with caffeine reducing perceived exertion, because exercise-to-exhaustion should end at the same point of fatigue. [69] Caffeine also improves power output and reduces time to completion in aerobic time trials, [70] an effect positively (but not exclusively) associated with longer duration exercise. [71] Specific populations AdultsChildren and young people who consume energy drinks containing caffeine may also suffer from sleep problems and anxiety. 5-7 Overdose

The F15 'key up' event is used every 59 seconds. This is the traditional behavior so is well tested, but can cause issues with Putty sessions, PowerPoint, Google Docs or Smartsheet

Red Bull is one of the most well-known and popular high-caffeine brands on the market and has become synonymous with energy drinks. The company is also known for its support of high-octane sports, record-breaking stunts and up-and-coming electronic musicians. Another factor to consider when consuming energy drinks is that they tend to be high in sugar, which, similar to caffeine, is fine in moderation. To be mindful of this, however, we’ll also link to sugar-free versions of our favourite drinks where available. Caffeine increases intraocular pressure in those with glaucoma but does not appear to affect normal individuals. [135] Bordeaux B. Benefits and risks of caffeine and caffeinated beverages. https://www.uptodate.com/contents/search. Accessed March 16, 2022.