Peer-Reviewed Journal Details
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.
2019
July
Nutrients
Differential stimulation of post-exercise myofibrillar protein synthesis in humans following isonitrogenous, isocaloric pre-exercise feeding
Published
9 ()
Optional Fields
Amino acids Deuterium oxide Humans Protein synthesis Resistance training Skeletal muscle Whey proteins
11
7
1657
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.
2072-6643
10.3390/nu11071657
Grant Details