TY - JOUR
T1 - Effect of n-3 fatty acids on free tryptophan and exercise fatigue
AU - Huffman, Derek M.
AU - Altena, Thomas S.
AU - Mawhinney, Thomas P.
AU - Thomas, Tom R.
N1 - Funding Information:
Acknowledgements We thank Dr. Bryan Smith for his assistance with experiments and each of the subjects for their willing participation. This study was funded in part by the University of Missouri Alumni Association and the Elizabeth Hegarty Foundation.
Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2004/8
Y1 - 2004/8
N2 - Free tryptophan (Trp), which is augmented by liberated free fatty acids (FFA) from adipose tissue, can induce mental fatigue via serotonin during exercise. Since an attenuation in FFA has been observed with omega-3 fatty acid (n-3fa) use, our purpose was to examine the effect of n-3fa supplementation on free Trp availability and exercise fatigue. Ten recreationally trained men (n = 5) and women (n = 5), with maximal oxygen consumption (̇ VO2max)of 51.6 (3.0) and 44.3 (1.4) ml kg-1 min-1, respectively, were studied on two occasions following an overnight fast, before and after n-3fa supplementation (4 g day-1 for 4 weeks). The exercise trials consisted of a 75-min treadmill run at 60% ̇ VO2max followed immediately by a high-intensity incremental bout to fatigue. Measurements included exercise monitors, plasma volume (PV), triglycerides (TG), FFA, glycerol, lactate, and glucose. Free Trp and branched-chain amino acids (BCAA) were measured and correlated with time to fatigue; all blood variables were corrected for PV. Free Trp, lactate, glucose, FFA, and glycerol were not significantly different between trials, but TG (P<0.001) and the free Trp/BCAA ratio were significantly lower after n-3fa use [1.76 (0.18) × 10-2 μg ml-1] versus before supplementation [2.17 (0.22), P = 0.0331. There was a non-significant increase in time to fatigue after supplementation [10.2 (0.3) min] versus before n-3fa use [9.7 (0.2), P = 0.068], and a tendency for higher BCAA levels after supplementation, P = 0.068. However, neither free Trp nor the free Trp/BCAA ratio significantly predicted time to fatigue. In conclusion, n-3fa supplementation did not diminish free Trp concentrations or significantly improve endurance performance during a maximal bout of exercise.
AB - Free tryptophan (Trp), which is augmented by liberated free fatty acids (FFA) from adipose tissue, can induce mental fatigue via serotonin during exercise. Since an attenuation in FFA has been observed with omega-3 fatty acid (n-3fa) use, our purpose was to examine the effect of n-3fa supplementation on free Trp availability and exercise fatigue. Ten recreationally trained men (n = 5) and women (n = 5), with maximal oxygen consumption (̇ VO2max)of 51.6 (3.0) and 44.3 (1.4) ml kg-1 min-1, respectively, were studied on two occasions following an overnight fast, before and after n-3fa supplementation (4 g day-1 for 4 weeks). The exercise trials consisted of a 75-min treadmill run at 60% ̇ VO2max followed immediately by a high-intensity incremental bout to fatigue. Measurements included exercise monitors, plasma volume (PV), triglycerides (TG), FFA, glycerol, lactate, and glucose. Free Trp and branched-chain amino acids (BCAA) were measured and correlated with time to fatigue; all blood variables were corrected for PV. Free Trp, lactate, glucose, FFA, and glycerol were not significantly different between trials, but TG (P<0.001) and the free Trp/BCAA ratio were significantly lower after n-3fa use [1.76 (0.18) × 10-2 μg ml-1] versus before supplementation [2.17 (0.22), P = 0.0331. There was a non-significant increase in time to fatigue after supplementation [10.2 (0.3) min] versus before n-3fa use [9.7 (0.2), P = 0.068], and a tendency for higher BCAA levels after supplementation, P = 0.068. However, neither free Trp nor the free Trp/BCAA ratio significantly predicted time to fatigue. In conclusion, n-3fa supplementation did not diminish free Trp concentrations or significantly improve endurance performance during a maximal bout of exercise.
KW - Branched-chain amino acids
KW - Exercise
KW - Fish oil
KW - Free fatty acids
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U2 - 10.1007/s00421-004-1069-6
DO - 10.1007/s00421-004-1069-6
M3 - Article
C2 - 15052485
AN - SCOPUS:4544226377
SN - 1439-6319
VL - 92
SP - 584
EP - 591
JO - European Journal of Applied Physiology
JF - European Journal of Applied Physiology
IS - 4-5
ER -
