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1Department of Sports Studies, University of Stirling, Stirling, United Kingdom; Departments of 2Human Health and Nutritional Sciences and 3Animal and Poultry Science, University of Guelph, Guelph, Ontario; and 4Department of Medicine, McMaster University, Hamilton, Ontario, Canada
Submitted 15 April 2008 ; accepted in final form 20 June 2008
This study examined 1) the plasma taurine response to acute oral taurine supplementation (T), and 2) the effects of 7 days of T on muscle amino acid content and substrate metabolism during 2 h of cycling at
60% peak oxygen consumption (
O2peak). In the first part of the study, after an overnight fast, 7 volunteers (28 ± 3 yr, 184 ± 2 cm, 88.0 ± 6.6 kg) ingested 1.66 g oral taurine doses with breakfast (8 AM) and lunch (12 noon), and blood samples were taken throughout the day. In the second part of the study, eight men (22 ± 1 yr, 181 ± 1 cm, 80.9 ± 3.8 kg, 4.21 ± 0.16 l/min
O2peak) cycled for 2 h after 7 days of placebo (P) ingestion (6 g glucose/day) and again following 7 days of T (5 g/day). In the first part of the study, plasma taurine was 64 ± 4 µM before T and rose rapidly to 778 ± 139 µM by 10 AM and remained elevated at noon (359 ± 56 µM). Plasma taurine reached 973 ± 181 µM at 1 PM and was 161 ± 31 µM at 4 PM. In the second part of the study, seven days of T had no effect on muscle taurine content (mmol/kg dry muscle) at rest (P, 44 ± 15 vs. T, 42 ± 15) or after exercise (P, 43 ± 12 vs. T, 43 ± 11). There was no difference in muscle glycogen or other muscle metabolites between conditions, but there were notable interaction effects for muscle valine, isoleucine, leucine, cystine, glutamate, alanine, and arginine amino acid content following exercise after T. These data indicate that 1) acute T produces a 13-fold increase in plasma taurine concentration; 2) despite the ability to significantly elevate plasma taurine for extended periods throughout the day, 7 days of T does not alter skeletal muscle taurine content or carbohydrate and fat oxidation during exercise; and 3) T appears to have some impact on muscle amino acid response to exercise.
amino acids; cycling; muscle glycogen
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C. A. Goodman, D. Horvath, C. Stathis, T. Mori, K. Croft, R. M. Murphy, and A. Hayes Taurine supplementation increases skeletal muscle force production and protects muscle function during and after high-frequency in vitro stimulation J Appl Physiol, July 1, 2009; 107(1): 144 - 154. [Abstract] [Full Text] [PDF] |
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