Improvements in Athletic performance

• In 2015 Medicine and Science in Sports and Exercise published a double-blind study involving 13 elite female volleyball players in which 3 mg/kg caffeine (approx. 200 mg for a 145 lb female) from an energy drink improved performance in jumping, spiking and accuracy compared to a placebo drink. [Source]
• In 2010 the Journal of Research in Medical Sciences published a study involving 10 males athletes which found that Red Bull and Hype energy drinks both increased VO2 max (maximum amount of oxygen that can be utilized during intense exercise) and time to exhaustion when compared to a placebo. [Source]
• In 2009 the International Journal of Sport Nutrition and Exercise Metabolism published a double-blind, crossover study in which 6 male and 6 female athletes consumed either 500 ml (16.9 oz) Red Bull or a placebo drink 40 minutes before a simulated cycling time trial. The Red Bull consumers had better times compared to the placebo drink. [Source]
• In 2014 Amino Acids published a study in which 16 basketball players consumed either 3 mg/kg (equal to 231 mg for a 170 lb male) caffeine in the form of an energy drink or a placebo drink 60 minutes before performing shooting tests. The energy drink did not improve shooting accuracy, though it did significantly increase jump height. [Source]
• In 2012 the Public Library of Science published placebo-controlled a study involving 19 semi-professional soccer players which found that sugar-free Red Bull containing 3 mg/kg caffeine increased jump height and the ability to sprint repeatedly. [Source]
• In 2013 Amino Acids published a 16-subject, placebo-controlled trial which found that caffeinated energy drinks increased muscle power output when jumping and accelerated running pace and sprint velocity in female rugby players. [Source]
• In 2015 the International Journal of Sports Physiology and Performance published a placebo-controlled, crossover study in which 14 elite young tennis players demonstrated increased grip force, running pace and number of sprints when consuming an energy drink (3 mg/kg caffeine) 60 minutes before activity, when compared to a placebo drink. [Source]
• In 2016 the European Journal of Nutrition published a meta-analysis of 34 studies which found that energy drink ingestion improved performance in muscle strength and endurance as well as jumping and sport specific actions. The researchers note that the improvements in performance were associated with the dosage of taurine. [Source]
• In 2016 International Journal of Sports Nutrition and Exercise Metabolism published a crossover study which found that 13 elite field hockey players were able to run longer at high intensity when consuming a caffeine containing energy drink when compared to a placebo. [Source]

No change in performance

• In 2014 the Journal of the International Society of Sports Nutrition published a double-blind, placebo-controlled, crossover study involving 14 male soldiers which found that consuming one Red Bull containing 80 mg caffeine and 1000 mg taurine did not increase physical or cognitive ability during exercise. [Source]
• In 2012 the International Journal of Sport Nutrition and Exercise Metabolism published a double-blind, placebo-controlled, crossover study in which 20 NCAA division 1 footfall players did not see an increase in sprint performance after consuming a caffeine-taurine energy drink. [Source]
• In 2013 Nutrients published a crossover study in which 6 males runners consumed a Red Bull energy shot, a Guayaki Yerba Mate Organic Energy Shot and a placebo on three separate occasions and subsequently completed a 5 K time trial. No differences in performance were detected between either energy shot and the placebo. [Source]
• In 2015 the Journal of the International Society of Sports Nutrition published a crossover study in which 15 participants participants consumed 3 types of energy drinks (Red Bull, Monster, 5-Hour Energy) and a placebo (Squirt) during four 15-minute running sessions. The results showed that there was no significant reduction in oxygen consumption or perceived exertion. However, the authors note that time trials to exhaustion may better assess whether energy drinks can improve performance.[Source]
• In 2012 Amino Acids published a placebo-controlled, crossover study involving 15 female collegiate soccer players which found that 255 mL of Red Bull containing 1.3 mg/kg caffeine (equal to 83 mg for a 140 lb female) and 1000 mg taurine did not improve sprint performance, perceived exertion or heart rate during sprints. [Source]

Dosage to increase muscle performance

• In 2012 the Journal of the International Society of Sports Nutrition published a placebo-controlled study involving 12 participants which found that 1 mg caffeine per kg body weight did not increase maximal muscle power while 3 mg/kg did significantly improve both half squat and bench press maximal power. [Source]

Mood, Stress and mental performance levels

• In 2012 Psychopharmacology published an 81-participant, double-blind study which found that energy drinks containing glucose and caffeine improved mental performance and reduced anxiety and self-reported stress levels during firefighter training. [Source]

Negative cerebral effects

• In 2014 the European Journal of Nutrition published crossover study in which 25 healthy young males consumed a Red Bull on one occasion and a placebo drink on a second occasion. The results showed that, compared to the placebo, ingestion of the Red Bull had an overall negative effect with relation to blood flow – subjects showed increased blood pressure and reduced cerebral blood flow velocity (the rate at which blood is flowing in the brain). [Source]

Driving

• In 2011 Psychopharmacology published a double-blind, crossover study which found that during a 4-hour simulated driving session, when consumed after 2 hours of driving, Red Bull energy drink reduced weaving, speed variations and sleepiness and improved driving performance in 24 subjects when compared to a placebo energy drink (Red Bull without caffeine, B vitamins, taurine and glucuronolactone). [Source]
• In 2014 the Journal of Safety Research published a study involving 15 truck drivers who, before a monotonous, rural 150-minute drive, consumed either 500 mL of an energy drink (containing 160 mg of caffeine), 500 mL of an energy drink along with a 10 minute rest period or no energy drink without a rest. Energy drinkers had fewer lane departures and steering wheel deviations during the first 100 minutes of driving and energy drinkers who also rested after 100 min of driving had the best results and were able to maintain better vehicle control after the rest period. [Source]

Energy drinks in youth populations

• In 2014 Frontiers in Psychology published a study of 509 adolescents aged 11-16 which found that on average consuming one more energy drink a day was associated with more parent-reported problems with metacognition and more self-reported problems with behavior regulation. An overall negative effect on executive function was associated with regular consumption of energy drinks, even in moderate amounts. [Source]

Dietary associations

• In 2015 Perspectives in Public Health published a study of 585 college freshmen who reported their energy drink consumption as well as a variety of dietary behaviors over a 1-week period. Data showed that energy drinkers were more likely to be male with greater BMI and have lower intake of fruits, vegetables, milk and breakfast and higher intakes of soda and frozen meals. [Source]

Side effects

• In 2014 the International Journal of High Risk Behaviors & Addiction published a pilot, crossover study involving 1500 students aged 13-30 which showed that at least 30 percent of energy drink consumers experienced at least one adverse effect, with rapid heart beat (tachycardia) reported in 21 percent of cases. [Source]

Poor Sleep Quality

• In 2013 Health published a study of 2,458 college students which found that, based on a self-administered questionnaire, consumption of 3 or more energy drinks per week was associated with daytime dysfunction due to sleep loss, short sleep duration and use of sleep medication. [Source]