The Effects of Caffeine, Taurine or Caffeine-Taurine Co-Ingestion on Repeat-Sprint Cycling Performance and Physiological Responses

Purpose: This study investigated the effects of caffeine (C), taurine (T), caffeine and taurine co-ingestion (C+T) or placebo (P) on repeated Wingate cycling performance and associated physiological responses. Methods: Seven male team sports players participated in a randomised, single-blind, cross-over study, where they completed three Wingate tests, each separated by 2-min, an hour after ingesting: C (5 mg/kg BM), T (50 mg/kg BM), C+T (5 mg/kg BM + 50 mg/kg BM) or P (5 mg/kg BM) in a gelatine capsule. Performance was measured on an ergometer, whilst blood lactate, perceived exertion, heart rate (HR), mean arterial pressure (MAP) and rate pressure product (RPP) were measured at rest (pre-supplement), baseline (1-h post-supplement) and during and after exercise. Results: Magnitude-based inferences revealed that all of the supplements increased (small to moderate, likely to very likely) mean peak power (MPP), peak power (PP) and mean power (MP) compared to P, with greater MPP, PP and MP in T compared to C (small, possible). Intra-sprint fatigue index (%FIIntra) was greater in T compared to P and C (moderate, likely), whilst inter-sprint fatigue index (%FIInter) was lower in T compared to C (small, possible). C and C+T increased HR, MAP and RPP compared to P and T at baseline (moderate to very large, likely to most likely); however, these only remained higher in C compared to all conditions in the final sprint. Conclusions: T elicited greater improvements in performance compared to P, C or C+T, whilst reducing the typical chronotropic and pressor effects of C.