Journal Title (Medline/Pubmed accepted abbreviation): Int. J. Sport Nutr. Exerc. Metab .
Page numbers: 322-329
doi (if applicable):
Summary of Background and Research Design
Background:Many energy drinks include and tout taurine for its ergogenic effects but scientific evidence is lacking.
Hypothesis/Research Question:Does acute taurine intake (1.66 g) affect the average time it takes to complete a cycling time trial?
Subjects:11 endurance-trained male cyclists/triathletes
Experimental design:Randomized, crossover, counterbalanced, placebo-controlled, blinded experiment
Treatments and protocol:Participants arrived at the testing facility in the morning after an overnight fast. 1 hr before cycling, participants consumed 500 mL of a noncaloric sweetened drink with 1.66 g taurine or nothing added (control, placebo). Three performance trials were completed in which participants consumed taurine, the control (0 mg taurine), or a placebo (0 mg taurine but the participants were told the beverage had taurine). The participants rode 90 min at about 65% VO2max and then completed a time trial in which they cycled as fast as possible to complete 5 kJ of work/kg body mass. Expired pulmonary gases were sampled at 6x 3 min intervals at 12, 27, 42, 57, and 72 min. Heart rate and rating of perceived exertion (RPE) were measured immediately after gas sampling. Also after gas sampling, 5 mL/kg of a sports drink was consumed was consumed within 5 min to ensure proper hydration and replacement of carbohydrates and electrolytes. Rates of carbohydrate and fat oxidation were calculated from rates of CO2 produced and O2 consumed. Monetary prizes were awarded to those with the lowest average total performance time to encourage maximal effort.
Summary of research findings:
- No difference in the average time required to complete the time trial
- Neither average heart rate nor rating of perceived exertion (RPE) were different during the 90 min ride preceding the time trial.
- VO2 and VCO2 were not affected by taurine.
- There was significantly more fat oxidation (~16%) during the taurine time trial than with the placebo or the control (P = 0.038)
Interpretation of findings/Key practice applications:
Acute taurine ingestion did not improve the performance of cyclists in a time trial. Many available beverages that include taurine (and that have been shown to have ergogenic effects) also include caffeine and/or other ergogenic aids. This study does not discount taurine’s ability to improve the ergogenic effects of another supplement.
The subjects were not allowed to eat breakfast beforehand. This practice is not consistent with normal exercise routines. Although the subjects consumed a carbohydrate-containing sports drink during the 90 min pre-trial cycling period, this may not reflect their normal metabolism after having eaten a pre-exercise breakfast meal.