Effects of Whey and Collagen Protein Blend on Protein Synthesis Rates

Rationale: Protein ingestion stimulates muscle protein synthesis and augments the muscle protein synthetic response to a single exercise session. In support, protein supplementation has been shown to augment the gains in muscle mass and strength following resistance exercise training. The force generated by contracting muscle is transferred through a network of connective tissue proteins towards the bone. Consequently, remodeling of skeletal muscle connective tissue represents an essential component of skeletal muscle adaptation to exercise. The anabolic effect of a protein supplement is mainly determined by the plasma amino acid response after ingestion. Although whey protein is considered the preferred protein source to maximize myofibrillar protein synthesis rates, it contains insufficient glycine and proline to support the post-exercise increase in connective tissue protein synthesis rates. In contrast, collagen protein is rich in glycine and proline and has, therefore, been proposed as a preferred protein source to support connective tissue remodeling. Hence, the combined ingestion of whey plus collagen protein may therefore be preferred to stimulate both myofibrillar and collagen protein synthesis rates in skeletal muscle tissue. The most ideal protein supplement for stimulating both myofibrillar and collagen protein synthesis is one that gives a rapid initial rise in plasma amino acid concentrations including leucine, proline and glycine concentrations. However, the effect a blend of whey and collagen protein on myofibrillar and connective tissue protein synthesis rates is unknown. Objective: To assess the effect of a whey and collagen protein blend versus a placebo on myofibrillar and connective tissue protein synthesis rates in muscle obtained during recovery from exercise and rest in vivo in humans. Study design: Double-blind, parallel-group, placebo-controlled intervention study. Study population: 28 healthy recreationally active males (18-35 y; BMI: 1