The Effect of Acute Taurine Ingestion on Endurance Performance and Metabolism in Well-Trained Cyclists

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, similar to 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.