Native whey protein with high levels of leucine results in similar post-exercise muscular anabolic responses as regular whey protein: a randomized controlled trial. Issue 1 (21st November 2017)

• Record Type: Journal Article
• Authors: Hamarsland, Håvard; Nordengen, Anne Lene; Nyvik Aas, Sigve; Holte, Kristin; Garthe, Ina; Paulsen, Gøran; Cotter, Matthew; Børsheim, Elisabet; Benestad, Haakon B.; Raastad, Truls
• Is Part Of: Journal of the International Society of Sports Nutrition. Volume 14:Issue 1(2017)
• Publication Date: 2017-11-21
• Subjects: Skeletal muscle -- Supplementation -- Amino acids -- Protein quality -- Stable isotopes -- Resistance training -- Nutrition; Athletes -- Nutrition -- Periodicals; Exercise -- Physiological aspects -- Periodicals; 613.2024796
• DOI: 10.1186/s12970-017-0202-y
• Languages: English
• ISSNs: 1550-2783

Abstract

Abstract: Background: Protein intake is essential to maximally stimulate muscle protein synthesis, and the amino acid leucine seems to possess a superior effect on muscle protein synthesis compared to other amino acids. Native whey has higher leucine content and thus a potentially greater anabolic effect on muscle than regular whey (WPC-80). This study compared the acute anabolic effects of ingesting 2 × 20 g of native whey protein, WPC-80 or milk protein after a resistance exercise session. Methods: A total of 24 young resistance trained men and women took part in this double blind, randomized, partial crossover, controlled study. Participants received either WPC-80 and native whey ( n = 10), in a crossover design, or milk ( n = 12). Supplements were ingested immediately (20 g) and two hours after (20 g) a bout of heavy-load lower body resistance exercise. Blood samples and muscle biopsies were collected to measure plasma concentrations of amino acids by gas-chromatography mass spectrometry, muscle phosphorylation of p70S6K, 4E–BP1 and eEF-2 by immunoblotting, and mixed muscle protein synthesis by use of [ 2 H5 ]phenylalanine-infusion, gas-chromatography mass spectrometry and isotope-ratio mass spectrometry. Being the main comparison, differences between native whey and WPC-80 were analysed by a one-way ANOVA and comparisons between the whey supplements and milk were analysed by a two-way ANOVA. Results: Native whey increased blood leucine concentrations more than WPC-80 and milk ( P < 0.05). Native whey ingestion induced a greater phosphorylation of p70S6K than milk 180 min after exercise ( P = 0.03). Muscle protein synthesis rates increased 1–3 h hours after exercise with WPC-80 (0.119%), and 1–5 h after exercise with native whey (0.112%). Muscle protein synthesis rates were higher 1–5 h after exercise with native whey than with milk (0.112% vs. 0.064, P = 0.023). Conclusions: Despite higher-magnitude increases in blood leucine concentrations with native whey, it was not superior to WPC-80 concerning effect on muscle protein synthesis and phosphorylation of p70S6K during a 5-h post-exercise period. Native whey increased phosphorylation of p70S6K and muscle protein synthesis rates to a greater extent than milk during the 5-h post exercise period. Trial registration: This study was retrospectively registered at clinicaltrials.gov as NCT02968888 .