Resistance exercise enhances myofibrillar protein synthesis with graded intakes of whey protein in older men

Yifan Yang, Leigh Breen, Nicholas A Burd, Amy J Hector, Tyler A Churchward-Venne, Andrea R Josse, M A Tarnopolsky, Stuart M Phillips

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292 Citations (Scopus)


Feeding stimulates robust increases in muscle protein synthesis (MPS); however, ageing may alter the anabolic response to protein ingestion and the subsequent aminoacidaemia. With this as background, we aimed to determine in the present study the dose-response of MPS with the ingestion of isolated whey protein, with and without prior resistance exercise, in the elderly. For the purpose of this study, thirty-seven elderly men (age 71 (sd 4) years) completed a bout of unilateral leg-based resistance exercise before ingesting 0, 10, 20 or 40 g of whey protein isolate (W0-W40, respectively). Infusion of l-[1-13C]leucine and l-[ring-13C6]phenylalanine with bilateral vastus lateralis muscle biopsies were used to ascertain whole-body leucine oxidation and 4 h post-protein consumption of MPS in the fed-state of non-exercised and exercised leg muscles. It was determined that whole-body leucine oxidation increased in a stepwise, dose-dependent manner. MPS increased above basal, fasting values by approximately 65 and 90 % for W20 and W40, respectively (P <0·05), but not with lower doses of whey. While resistance exercise was generally effective at stimulating MPS, W20 and W40 ingestion post-exercise increased MPS above W0 and W10 exercised values (P <0·05) and W40 was greater than W20 (P <0·05). Based on the study, the following conclusions were drawn. At rest, the optimal whey protein dose for non-frail older adults to consume, to increase myofibrillar MPS above fasting rates, was 20 g. Resistance exercise increases MPS in the elderly at all protein doses, but to a greater extent with 40 g of whey ingestion. These data suggest that, in contrast to younger adults, in whom post-exercise rates of MPS are saturated with 20 g of protein, exercised muscles of older adults respond to higher protein doses.
Original languageEnglish
Pages (from-to)1780-8
Number of pages9
JournalThe British journal of nutrition
Issue number10
Publication statusPublished - 28 Nov 2012


  • Amino Acids
  • Food Analysis
  • Humans
  • Aged
  • Exercise
  • Insulin
  • Myofibrils
  • Dietary Supplements
  • Gene Expression Regulation
  • Milk Proteins
  • Diet
  • Male
  • Carbon Isotopes


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