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Mandatory Fields
Davies R.;Bass J.;Carson B.;Norton C.;Kozior M.;Amigo-Benavent M.;Jakeman P.;Wilkinson D.;Brook M.;Atherton P.;Smith K.
Differential stimulation of post-exercise myofibrillar protein synthesis in humans following isonitrogenous, isocaloric pre-exercise feeding
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Optional Fields
Amino acids Deuterium oxide Humans Protein synthesis Resistance training Skeletal muscle Whey proteins
2019 by the authors. Licensee MDPI, Basel, Switzerland. The aim of this study was to test the effects of two disparate isonitrogenous, isocaloric pre-exercise feeds on deuterium-oxide (D2O) derived measures of myofibrillar protein synthesis (myoPS) in humans. Methods: In a double-blind parallel group design, 22 resistance-trained men aged 18 to 35 years ingested a meal (6 kcalkg-1, 0.8 gkg-1 carbohydrate, 0.2 gkg-1 fat) with 0.33 gkg-1 nonessential amino acids blend (NEAA) or whey protein (WHEY), prior to resistance exercise (70% 1RM back-squats, 10 reps per set to failure, 25% duty cycle). Biopsies of M. vastus lateralis were obtained pre-ingestion (PRE) and +3 h post-exercise (POST). The myofibrillar fractional synthetic rate (myoFSR) was calculated via deuterium labelling of myofibrillar-bound alanine, measured by gas chromatography-pyrolysis-isotope ratio mass spectrometry (GC-Pyr-IRMS). Data are a mean percentage change (95% CI). Results: There was no discernable change in myoFSR following NEAA (10(-5, 25) %, p = 0.235), whereas an increase in myoFSR was observed after WHEY (28 (13, 43) %, p = 0.003). Conclusions: Measured by a D2O tracer technique, a disparate myoPS response was observed between NEAA and WHEY. Pre-exercise ingestion of whey protein increased post-exercise myoPS, whereas a NEAA blend did not, supporting the use of NEAA as a viable isonitrogenous negative control.
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