Table 8.
Energy drinks and pre-workout supplements
| Author | Participants | Protocol | Results | Other supplements | |
|---|---|---|---|---|---|
| Endurance Exercise Performance | Alford et al. 2001 [85] | Young adults (n = 36) |
-250 mL Energy drink with 80 mg caffeine and 26 g CHO -Carbonated placebo -No drink |
*↑ Aerobic Endurance | -26 g CHO |
| Candow et al. 2009 [86] | Young men (n = 9) and women (n = 8) |
-CHO free energy drink with 2 mg/kg caffeine -Non-caffeinated version of energy drink |
⬌ High-intensity Run Time to Exhaustion | ||
| Walsh et al. 2010 [87] | Recreationally active men (n = 9) and women (n = 6) |
-26 g Pre-workout with unknown amount of caffeine (ingredients listed in column 5) -Placebo |
*↑ Mod-intensity Run Time to Exhaustion | −2.05 g taurine, caffeine, and gluconolactone, 7.9 g L-leucine, L-isoleucine, L-valine, L-arginine and L-glutamine, 5 g of di-creatine citrate, and 2.5 g of βalanine | |
| Ivy et al. 2009 [88] | Trained cyclists men (n = 6) and women (n = 6) |
-Energy drink with 160 mg caffeine -Placebo |
*↑ Cycle Time Trial Performance by 4.7% | -2.0 g taurine, 1.2 g glucuronolactone, 54 g carbohydrate, 40 mg niacin, 10 mg pantothenic acid, 10 mg vitamin B6, and 10 microg vitamin B12 | |
| Sanders et al. 2015 [89] | Healthy participants (n = 15) |
−12 oz. Placebo (Squirt) − 8.4 oz. Red Bull® − 16 oz. Monster Energy® − 2 oz. 5-h ENERGY® |
⬌ RPE on Treadmill at 70% VO2 max ⬌ Oxygen Consumption at 70% VO2 max |
||
| Al-Fares et al. 2015 [90] | Healthy female students (n = 32) |
-Energy drink with 160 mg caffeine -Placebo with similar CHO content |
⬌ VO2 max | −2.0 g taurine, 1.2 g glucuronolactone, 54 g carbohydrate, 40 mg niacin, 10 mg pantothenic acid, 10 mg vitamin B6, and 10 μg vitamin B12 | |
| Prins et al. 2016 [91] | Recreation endurance male (n = 13) and female (n = 5) runners |
-Energy drink with 160 mg caffeine -Placebo |
*↑ 5 k Time Trial | −2.0 g taurine, 1.2 g glucuronolactone, 54 g carbohydrate, 40 mg niacin, 10 mg pantothenic acid, 10 mg vitamin B6, and 10 microg vitamin B12 | |
| Kinsinger et al. 2016 [92] | Recreational male athletes (n = 23) |
−1.93 oz Energy shot with 100 mg caffeine − 1.93 oz. Placebo |
⬌ RPE on Treadmill VO2 max Test ⬌ Treadmill VO2 max |
-1870 mg (taurine, glucuronic acid, malic acid, N-acetyl L-tyrosine, L-phenylalanine and citicoline) | |
| Resistance/Sprint Performance | Forbes et al. 2007 [93] | Young men (n = 11) and women (n = 40 |
-Energy drink with 2 mg/kg caffeine -Non-caffeinated version of energy drink |
*↑ Bench-Press Repetitions by 6% | |
| Del Coso et al. 2012 [94] | Healthy men (n = 9) and women (n = 3) |
-Energy drink with 1 mg/kg caffeine -Energy drink with 3 mg/kg caffeine -Non-caffeinated version of energy drink |
*↑ Half-Squat Maximal Power by 7% *↑ Bench-Press Maximal Power by 7% |
||
| Gonzalez et al. 2011 [95] | Resistance-trained college males (n = 8) |
−26 g Pre-workout with unknown amount of caffeine (ingredients listed in column 5) -Placebo |
*↑ # of Bench-Press and Squat Repetitions at 80% 1RM by 11.8% *↑ Average Power Output for the Workout |
-2.05 g taurine, caffeine, and gluconolactone, 7.9 g L-leucine, L-isoleucine, L-valine, L-arginine and L-glutamine, 5 g of di-creatine citrate, and 2.5 g of βalanine | |
| Astorino et al. 2011 [96] | Collegiate female soccer players (n = 15) |
-255 mL energy drink with 1.3 mg/kg caffeine + 1 g taurine -Placebo |
⬌ Sprint-based Exercise Performance | -1 g taurine | |
| Campbell et al. 2016 [97] | College men (n = 8) and women (n = 11) |
-37 mL Energy shot with 2.4 mg/kg caffeine -37 mL Placebo |
⬌ Vertical Jump ⬌ YMCA Bench-Press NS↑ Curl-up Endurance |
||
| Eckerson et al. 2013 [98] | Resistance-trained men (n = 17) |
−500 mL Energy drink with 160 mg caffeine + 2 g taurine − 500 mL Energy drink with 160 mg caffeine − 500 mL Placebo |
⬌ 1RM Bench-Press Strength ⬌ Total Volume Lifted |
−2 g Taurine | |
| Astley et al. 2018 [99] | Resistance-trained men (n = 15) |
-Energy drink with 2.5 mg/kg caffeine -Non-caffeinated version of energy drink |
*↑ Knee Extensions in Dominant Leg *↑ 80% 1RM Bench-Press Reps *↑ Isometric Grip Strength |
||
| Magrini et al. 2016 [100] | Healthy men (n = 23) and women (n = 8) |
-4 oz Energy drink with 158 mg caffeine -4 oz. Placebo |
⬌ Total Push-ups | ||
| Anaerobic Exercise Performance for Power | Forbes et al. 2007 [93] | Young men (n = 11) and women (n = 4) |
-Energy drink with 2 mg/kg caffeine -Non-caffeinated version of energy drink |
⬌ Wingate Peak Power ⬌ Wingate Average Power |
|
| Campbell et al. 2010 [101] | Recreationally active young men (n = 9) and women (n = 6) |
-Energy drink with 2.1 mg/kg caffeine -Non-caffeinated version of energy drink |
⬌ Wingate Peak Power | ||
| Hoffman et al. 2009 [102] | Male strength/power athletes (n = 12) |
-Energy drink with 1.8 mg/kg caffeine -Non-caffeinated version of energy drink |
⬌ Wingate Power Performance | ||
| Alford et al. 2001 [85] | Young adults (n = 36) |
−250 mL Energy drink with 80 mg caffeine and 26 g CHO -Carbonated placebo -No drink |
*↑ Maximum Speed on Cycle Ergometer | -26 g CHO | |
| Campbell et al. 2016 [97] | College men (n = 8) and women (n = 11) |
-37 mL Energy shot with 2.4 mg/kg caffeine -37 mL Placebo |
⬌ Repeated Sprint Speed | ||
| Mood/ Reaction Time/ Alertness | Alford et al. 2001 [85] | Young adults (n = 36) |
-250 mL Energy drink with 80 mg caffeine and 26 g CHO -Carbonated placebo -No drink |
*↑ Choice Reaction Time *↑ Concentration *↑ Memory |
-26 g CHO |
| Walsh et al. 2010 [87] | Recreationally active men (n = 9) and women (n = 6) |
-26 g Pre-workout with unknown amount of caffeine (ingredients listed in column 5) -Placebo |
*↑ Focus and Energy in 1st 10 min of Exercise ⬌ Energy, Fatigue, and Focus Immediately Post-exercise |
-2.05 g taurine, caffeine, and gluconolactone, 7.9 g L-leucine, L-isoleucine, L-valine, L-arginine and L-glutamine, 5 g of di-creatine citrate, and 2.5 g of βalanine | |
| Hoffman et al. 2009 [102] | Male strength/power athletes (n = 12) |
-Energy drink with 1.8 mg/kg caffeine -Non-caffeinated version of energy drink |
*↓ Reaction Time *↑ Feelings of Energy and Focus NS↑ Alertness |
||
| Seidl et al. 2000 [103] | Male (n = 4) and female (n = 6) graduate students |
-Energy drink with 160 mg caffeine -Placebo |
*↓ Reaction Time at Night ⬌ Vitality Scores at Night [[when compared to the Placebo Group who saw a significant decline in vitality and response time]] |
2.0 g taurine, 1.2 g glucuronolactone, 54 g carbohydrate, 40 mg niacin, 10 mg pantothenic acid, 10 mg vitamin B6, and 10 microg vitamin B12 | |
| Scholey et al. 2004 [104] | Healthy volunteers (n = 20) |
-250 ml Energy drink with 75 mg caffeine -Non-caffeinated version of energy drink -Placebo |
*↑ Secondary Memory *↑ Speed of Attention |
−37.5 g glucose, ginseng, and Ginkgo biloba | |
| Smit et al. 2004 [105] | Healthy volunteers (n = 271) |
-Caffeine + CHO + Carbonation -Placebo with carbonation -Placebo without carbonation |
⬌ Mood and Performance (during fatiguing and cognitively demanding tasks) | -CHO | |
| Rao et al. 2005 [106] | Healthy volunteers (n = 40) |
-Caffeine + CHO -Placebo |
*↑ Event Related Potentials in ECGs *↑ Behavioral Performance in Accuracy and Speed of Performance |
-CHO | |
| Howard et al. 2010 [107] | College students (n = 80) |
-Energy drink with 1.8 ml/kg caffeine** -Energy drink with 3.6 ml/kg caffeine -Energy drink with 5.4 ml/kg caffeine -Non-caffeinated version of energy drink -No drink |
Compared with the placebo and no drink conditions, the energy drink doses decreased reaction times on the behavioral control task, increased subjective ratings of stimulation and decreased ratings of mental fatigue. Greatest improvements in reaction times and subjective measures were observed with the lowest dose (1/8 mg/kg). |
Taurine, sucrose and glucose, B-group vitamins | |
| Wesnes et al. 2016 [108] | Young volunteers (n = 24) |
-250 mL Energy drink with 80 mg caffeine + 27 g glucose -250 mL Energy drink with 80 mg caffeine -250 mL Placebo |
*↑ Working and Episodic Memory | -27 g Glucose |
Outcomes are bold group specific; * = significant difference, ⬌ = no change, ↑ = improved performance, ↓ = decrease, TT = time trial, RPA = rating of perceived exertion, NS = non-significant improvement, mg/kg = milligram per kilogram, g = grams, CHO = carbohydrate, min = minutes, VO2 = aerobic capacity, m = meters, ml = milliliters, RPE = rating of perceived exertion