Red Bull is a popular energy drink that many athletes and even some non-athletes use as a quick pick-me-up. I never use it myself, but I have little doubt that it works since it has a lot of caffeine, as well as sugar. Besides this it also has B vitamins, and taurine.
The effect of the caffeine in Red Bull is nothing to be skeptical about, but I have been skeptical about the effects of taurine, an organic acid: Is Red Bull’s taurine content also responsible for the stimulating effect it provides?
According to the University of Stirling, Scotland, UK, in The effect of acute taurine ingestion on 3-km running performance in trained middle-distance runners:
Limited research examining the effect of taurine (TA) ingestion on human exercise performance exists. The aim of this study was to investigate the effect of acute ingestion of 1,000 mg of TA on maximal 3-km time trial (3KTT) performance in trained middle-distance runners (MDR). Eight male MDR (mean ± SD: age 19.9 ± 1.2 years, body mass 69.4 ± 6.6 kg, height 180.5 ± 7.5 cm, 800 m personal best time 121.0 ± 5.3 s) completed TA and placebo (PL) trials 1 week apart in a double-blind, randomised, crossover designed study. Participants consumed TA or PL in capsule form on arrival at the laboratory followed by a 2-h ingestion period. At the end of the ingestion period, participants commenced a maximal simulated 3KTT on a treadmill. Capillary blood lactate was measured pre- and post-3KTT. Expired gas, heart rate (HR), ratings of perceived exertion (RPE), and split times were measured at 500-m intervals during the 3KTT. Ingestion of TA significantly improved 3KTT performance (TA 646.6 ± 52.8 s and PL 658.5 ± 58.2 s) (p = 0.013) equating to a 1.7 % improvement (range 0.34-4.24 %). Relative oxygen uptake, HR, RPE and blood lactate did not differ between conditions (p = 0.803, 0.364, 0.760 and 0.302, respectively). Magnitude-based inference results assessing the likeliness of a beneficial influence of TA were 99.3 %. However, the mechanism responsible for this improved performance is unclear. TA’s potential influence on exercise metabolism may involve interaction with the muscle membrane, the coordination or the force production capability of involved muscles. Further research employing more invasive techniques may elucidate TA’s role in improving maximal endurance performance.
This is all so preliminary, but can a “1.7 % improvement” really be called significant? I’m no expert on this subject or when it comes to statistics, but this doesn’t seem big enough to me to justify its use. We need to see what similar studies say on this matter.
I managed to find a study about taurine supplementation in cyclists done by the University of Guelph, Ontario, Canada, which found that:
This study examined whether acute taurine (T) ingestion before prolonged cycling would improve time-trial (TT) performance and alter whole-body fuel utilization compared with a control (CON) trial and a placebo (PL) trial in which participants were told they received taurine but did not. Eleven endurance-trained male cyclists (27.2 ± 1.5 yr, 74.3 ± 2.3 kg, 59.9 ± 2.3 ml · kg⁻¹ · min⁻¹; M ± SEM) completed 3 trials in a randomized, crossover, blinded design in which they consumed a noncaloric sweetened beverage with either 1.66 g of T or nothing added (CON, PL) 1 hr before exercise. Participants then cycled at 66.5% ± 1.9% VO(2max) for 90 min followed immediately by a TT (doing 5 kJ of work/kg body mass as fast as possible). Data on fluid administration, expired gas, heart rate, and ratings of perceived exertion were collected at 15-min intervals during the 90-min cycling ride, but there were no differences recorded between trials. There was no difference in TT performance between any of the 3 trials (1,500 ± 87 s). Average carbohydrate (T 2.73 ± 0.21, CON 2.88 ± 0.19, PL 2.89 ± 0.20 g/min) and fat (T 0.45 ± 0.05, CON 0.39 ± 0.04, PL 0.39 ± 0.05 g/min) oxidation rates were unaffected by T supplementation. T ingestion resulted in a 16% increase (5 g, ~84 kJ; p < .05) in total fat oxidation over the 90-min exercise period compared with CON and PL. The acute ingestion of 1.66 g of T before exercise did not enhance TT performance but did result in a small but significant increase in fat oxidation during submaximal cycling in endurance-trained cyclists.
Taurine supplementation did not improve performance but did improve fat oxidation by a small amount. I realize the first study was done on runners and the second study on cyclists, but the exercises are both cardio and similar enough for comparison purposes.
So it looks like it is the caffeine and sugars that are exclusively responsible for Red Bull’s effects. The jury is still out on the taurine(B vitamins are also in Red Bull, but that is beyond the scope of this post).