Purpose: To examine the effect of taurine ingestion on maximal voluntary muscle torque and power in trained male athletes with different caffeine habits.
Methods: Fourteen male athletes aged 21.8 +/- 2.5 years were separated into caffeine and non-caffeine consumers to control for the effect of caffeine withdrawal on muscle function. On separate occasions, participants performed four isokinetic or three maximal isometric knee extensions with and without taurine (40 mg/kg body mass) following a double blind, counterbalanced design. Muscle contractile performances were compared between the first sets as well as between the sets where these variables scored best.
Results: In response to isokinetic contraction, taurine treatment in the non-caffeine consumers resulted in a significant fall in first (-16.1%; p=0.013) and best peak torque (-5.0%; p=0.016) as well as in first (-17.7%; p=0.015) and best power output (-8.0%; p=0.008). In the caffeine consumers deprived of caffeine, taurine intake improved best power (5.2%; p=0.045). With respect to the isometric variables, there was a significant decrease in the first (-5.1%; p=0.002) and best peak torque (-4.3%; p=0.032) in the non-caffeine group, but no effect in the group of caffeine consumers deprived of caffeine. Taurine ingestion increased blood taurine levels, but had no effect on plasma amino acid levels.
Conclusion: Taurine ingestion is detrimental to maximal voluntary muscle power and both maximal isokinetic and isometric peak torque in non-caffeine consumers, whereas taurine ingestion in caffeine-deprived caffeine consumers improves maximal voluntary muscle power but has not effect on other aspects of contractile performance.
(C) 2017 American College of Sports Medicine