2018-02-02, 12:50
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#1
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Chefsarkitekt Oljebyxor
Reg.datum: Mar 2002
Ort: Norrtälje
Inlägg: 78 268
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Arakidonsyra och anabol effekt hos tränade män
Citat:
Arachidonic acid (ARA), a polyunsaturated ω-6 fatty acid, acts as precursor to a number of prostaglandins with potential roles in muscle anabolism. It was hypothesized that ARA supplementation might enhance the early anabolic response to resistance exercise (RE) by increasing muscle protein synthesis (MPS) via mammalian target of rapamycin (mTOR) pathway activation, and/or the late anabolic response by modulating ribosome biogenesis and satellite cell expansion. Nineteen men with {greater than or equal to}1 year of resistance training experience were randomized to consume either 1.5 grams daily of ARA or a corn-soy oil placebo in a double-blind manner for 4-weeks. Participants then undertook fasted RE (8 sets each of leg press and extension at 80% 1RM), with vastus lateralis biopsies obtained before exercise, immediately post-exercise, and at 2, 4 and 48 hours of recovery. MPS (measured via stable isotope infusion) was not different between groups (P=0.212) over the 4-hour recovery period. mTOR pathway members p70S6K and rpS6 were phosphorylated post-exercise (P<0.05), with no difference between groups. 45S pre-ribosomal RNA (rRNA) increased 48 hours after exercise only in ARA (P=0.012). NCAM+ satellite cells per fibre were increased 48 hours after exercise (P=0.013), with no difference between groups (P=0.331). Prior ARA supplementation did not alter the acute anabolic response to RE in previously resistance trained men; however, at 48 of recovery, ribosome biogenesis was stimulated only in the ARA group. The findings do not support a mechanistic link between ARA and short-term anabolism, but ARA supplementation in conjunction with resistance training may stimulate increases in translational capacity.
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J Appl Physiol (1985). 2018 Feb 1. The effect of dietary arachidonic acid supplementation on acute muscle adaptive responses to resistance exercise in trained men: a randomized controlled trial.
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