The effect of acute taurine ingestion on 4-km time trial performance in trained cyclists.

Taurine (TAU) has been shown to improve exercise time to exhaustion and 3-km running performance; however, no studies have considered the effect of acute TAU ingestion on short duration cycling time trial (TT) performance. The aim of this study was to determine the effects of a single oral acute dose of 1000 mg of TAU on a laboratory simulated 4-km cycling TT. Eleven trained male cyclists performed three, 4-km TTs. The first of the trials was a familiarisation, followed by two subsequent trials which were performed two hours after the consumption of either 1000 mg of TAU or placebo (P), using a double-blind randomised crossover design. Capillary blood samples were obtained prior to the start and immediately after each TT for the measurement of lactate, pH and HCO. There was no effect of TAU (p = 0.731, d = 0.151) on performance (390 ± 27 and 388 ± 21 s for TAU and P, respectively), nor were there any condition main effects for VO, lactate, pH, or HCO (p > 0.05) despite post TT changes in lactate (7.3 ± 2.5 mmol l, p < 0.001, d = 2.86, 7.6 ± 2.0 mmol l p < 0.001, d = 3.75); pH (-0.255 ± 0.1, p < 0.001, d = 2.62, -0.258 ± 0.09, p < 0.001, d = 2.87); HCO (-13.58 ± 2.7 mmol l, p < 0.001, d = 5.04 vs. -13.36 ± 2.3, p < 0.001, d = 5.72 for TAU and P, respectively). The findings of this study suggest that a pre-exercise dose of 1000 mg TAU offers no performance advantage during 4-km TT nor does it alter the blood buffering responses in trained cyclists.