Myofibrillar and Mitochondrial Protein Synthesis Rates Do Not Differ in Young Men Following the Ingestion of Carbohydrate with Whey, Soy, or Leucine-Enriched Soy Protein after Concurrent Resistance- and Endurance-Type Exercise

• Published in: The Journal of nutrition 2019-02, Vol.149 (2), p.210-220
• Main Authors: Churchward-Venne, Tyler A, Pinckaers, Philippe J M, Smeets, Joey S J, Peeters, Wouter M, Zorenc, Antoine H, Schierbeek, Henk, Rollo, Ian, Verdijk, Lex B, van Loon, Luc J C
• Format: Article
• Language: English
• Subjects: carbohydrate; Carbohydrates; concurrent exercise; Dietary Carbohydrates - administration & dosage; dietary protein; Double-Blind Method; Enrichment; Exercise physiology; Humans; Ingestion; Leucine; Leucine - administration & dosage; Leucine - metabolism; Male; Men; Mens health; Milk Proteins - administration & dosage; Mitochondria; Mitochondria - drug effects; Mitochondria - metabolism; muscle protein synthesis; Muscles; Muscular system; Myofibrils - metabolism; Original; Phenylalanine; Physical Endurance; Protein biosynthesis; Protein Biosynthesis - drug effects; Protein synthesis; Proteins; Rapamycin; Recovery; Resistance Training; Signaling; soy; Soybean Proteins - administration & dosage; Soybean Proteins - metabolism; TOR protein; Tyrosine; Whey; Whey - administration & dosage; Whey protein; Young Adult; young men
• ISSN: 0022-3166; 1541-6100
• DOI: 10.1093/jn/nxy251

Protein ingestion during recovery from resistance-type exercise increases postexercise muscle protein synthesis rates. Whey protein has been reported to have greater anabolic properties than soy protein, an effect which may be attributed to the higher leucine content of whey. The objective of this study was to compare postprandial myofibrillar (MyoPS) and mitochondrial (MitoPS) protein synthesis rates after ingestion of carbohydrate with whey, soy, or soy protein enriched with free leucine (to match the leucine content of whey) during recovery from a single bout of concurrent resistance- and endurance-type exercise in young healthy men. In a randomized, double-blind, parallel-group design, 36 healthy young recreationally active men (mean ± SEM age: 23 ± 0.4 y) received a primed continuous infusion of l-[ring-13C6]-phenylalanine and l-[ring-3,5-2H2]-tyrosine and ingested 45 g carbohydrate with 20 g protein from whey (WHEY), soy (SOY), or leucine-enriched soy (SOY + LEU) after concurrent resistance- and endurance-type exercise. Blood and muscle biopsies were collected over a 360 min postexercise recovery period to assess MyoPS and MitoPS rates, and associated signaling through the mammalian target of rapamycin complex 1 (mTORC1). Postprandial peak plasma leucine concentrations were significantly higher in WHEY (mean ± SEM: 322 ± 10 μmol/L) and SOY + LEU (328 ± 14 μmol/L) compared with SOY (216 ± 6 μmol/L) (P