Positive effects of Red Bull® Energy Drink on driving performance during prolonged driving.
BACKGROUND
The purpose of this study was to examine if Red Bull® Energy Drink can counteract sleepiness and driving impairment during prolonged driving.


METHODS
Twenty-four healthy volunteers participated in this double-blind placebo-controlled crossover study. After 2 h of highway driving in the STISIM driving simulator, subjects had a 15-min break and consumed Red Bull® Energy Drink (250 ml) or placebo (Red Bull® Energy Drink without the functional ingredients: caffeine, taurine, glucuronolactone, B vitamins (niacin, pantothenic acid, B6, B12), and inositol) before driving for two additional hours. A third condition comprised 4 h of uninterrupted driving. Primary parameter was the standard deviation of lateral position (SDLP), i.e., the weaving of the car. Secondary parameters included SD speed, subjective driving quality, sleepiness, and mental effort to perform the test.


RESULTS
No significant differences were observed during the first 2 h of driving. Red Bull® Energy Drink significantly improved driving relative to placebo: SDLP was significantly reduced during the 3rd (p < 0.046) and 4th hour of driving (p < 0.011). Red Bull® Energy Drink significantly reduced the standard deviation of speed (p < 0.004), improved subjective driving quality (p < 0.0001), and reduced mental effort to perform the test (p < 0.024) during the 3rd hour of driving. Subjective sleepiness was significantly decreased during both the 3rd and 4th hour of driving after Red Bull® Energy Drink (p < 0.001 and p < 0.009, respectively). Relative to uninterrupted driving, Red Bull® Energy Drink significantly improved each parameter.


CONCLUSIONS
Red Bull® Energy Drink significantly improves driving performance and reduces driver sleepiness during prolonged highway driving.
Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, P.O. Box 80082, 3508 TB, Utrecht, The Netherlands.
Monique A J
MA
Mets
Sander
S
Ketzer
Camilla
C
Blom
Maartje H
MH
van Gerven
Gitta M
GM
van Willigenburg
Berend
B
Olivier
Joris C
JC
Verster
D000328:Adult; D000704:Analysis of Variance; D001333:Automobile Driver Examination; D001334:Automobile Driving; D001628:Beverages; D002110:Caffeine / Q000494:pharmacology*; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004734:Energy Metabolism / Q000187:drug effects; D005221:Fatigue / Q000188:drug therapy* / Q000503:physiopathology; D015673:Fatigue Syndrome, Chronic / Q000188:drug therapy / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D009048:Motor Skills / Q000187:drug effects*; D012890:Sleep / Q000187:drug effects / Q000502:physiology; D013997:Time Factors; D055815:Young Adult
D000697:Central Nervous System Stimulants; D002110:Caffeine