Even effect of milk protein and carbohydrate intake but no further effect of heavy resistance exercise on myofibrillar protein synthesis in older men

Research output: Contribution to journalArticlepeer-review

Authors

  • Søren Reitelseder
  • Kasper Dideriksen
  • Jakob Agergaard
  • Nikolaj M Malmgaard-Clausen
  • Rasmus L Bechshoeft
  • Rasmus K Petersen
  • Anja Serena
  • Ulla R Mikkelsen

Colleges, School and Institutes

External organisations

  • Institute of Sports Medicine Copenhagen, Department of Orthopedic Surgery M, Bispebjerg Hospital and Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Bispebjerg Bakke 23, building 8, 1st floor, 2400, Copenhagen NV, Denmark. soeren.reitelseder@regionh.dk.
  • Institute of Sports Medicine Copenhagen, Department of Orthopedic Surgery M, Bispebjerg Hospital and Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Bispebjerg Bakke 23, building 8, 1st floor, 2400, Copenhagen NV, Denmark.
  • Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark.
  • Arla Foods amba, Viby J, Denmark.
  • Arla Foods Ingredients Group P/S, Viby J, Denmark.

Abstract

PURPOSE: The responsiveness of older individuals' skeletal muscle to anabolic strategies may be impaired. However, direct comparisons within the same experimental setting are sparse. The aim of this study was to assess the resting and post-resistance exercise muscle protein synthesis rates in response to two types of milk protein and carbohydrate using a unilateral exercise leg model.

METHODS: Twenty-seven older (69 ± 1 year, mean ± SE) men were randomly assigned one of three groups: Whey hydrolysate (WH), caseinate (CAS), or carbohydrate (CHO). By applying stable isotope tracer techniques (L-[15N]phenylalanine), the fasted-rested (basal) myofibrillar fractional synthesis rate (FSR) was measured. Hereafter, FSR was measured in the postprandial phase (0.45 g nutrient/kg LBM) in both legs, one rested (fed-rest) and one exercised (10 × 8 reps at 70% 1RM; fed-exercise). In addition, the activity of p70S6K and venous plasma insulin, phenylalanine, and leucine concentrations were measured.

RESULTS: Insulin, phenylalanine, and leucine concentrations differed markedly after intake of the different study drinks. The basal FSR in WH, CAS, and CHO were 0.027 ± 0.003, 0.030 ± 0.003, and 0.030 ± 0.004%/h, the fed-rested FSR were 0.043 ± 0.004, 0.045 ± 0.003, and 0.035 ± 0.004%/h, and the fed-exercised FSR were 0.041 ± 0.004, 0.043 ± 0.004, and 0.034 ± 0.004%/h, respectively. No significant differences were observed at any state between the groups. Fed-rested- and fed-exercised FSR were higher than basal (P < 0.001). 3 h after exercise and feeding, no significant group differences were detected in the activity of p70S6K.

CONCLUSIONS: Milk protein and carbohydrate supplementation stimulate myofibrillar protein synthesis in older men, with no further effect of heavy resistance exercise within 0-3 h post exercise.

Details

Original languageEnglish
JournalEuropean Journal of Nutrition
Early online date22 Feb 2018
Publication statusE-pub ahead of print - 22 Feb 2018

Keywords

  • Journal Article, Muscle protein synthesis, anabolic resistance, Caseinate, Sarcopenia, whey hydrolysate