The Effects of Varying Protein Intakes on Muscle Protein Synthesis During Injury-Mediated Muscle Disuse

What this Trial Is About

Researchers are studying how different amounts of dietary protein affect muscle protein synthesis in healthy, active adults who experience muscle disuse due to injury. The study focuses on overcoming muscle loss caused by reduced muscle use, which leads to a negative balance between muscle protein breakdown and synthesis. This work aims to identify the optimal protein dose to stimulate muscle rebuilding during periods of immobilization to improve recovery from musculoskeletal injuries. Participants will undergo a randomized, double-blind study where one leg is immobilized using a knee brace fixed at about 60 degrees of flexion for five days, while the other leg remains active as a control. During immobilization, diets will be standardized. After this phase, participants will consume either 20 grams or 40 grams of whey protein as a beverage to evaluate muscle protein synthesis responses in both legs. Throughout the study, participants will undergo stable isotope infusions, blood draws, and muscle biopsies to measure muscle protein synthesis rates. Researchers will assess how muscle responds to the protein doses after immobilization, using advanced methods like 2H5-Phenylalanine stable isotope techniques. The trial will help develop nutritional strategies to preserve muscle mass and support recovery after injury. The study includes careful monitoring of diet, physical activity, and safety, with participation lasting at least the immobilization and protein feeding phases.

Muscle Response to Different Amounts of Dietary Protein During Leg Immobilization