4 Clinical Trials for Various Conditions
In a crossover design 10 young healthy adults (20-35 y) will receive stable isotope tracer infusions and perform a single bout of resistance exercise. Immediately after exercise participants will ingest either 246 g of rice and beans or its constituent macronutrients as isolated amino acids, carbohydrates, fiber, and fat. Repeated blood and muscle biopsies will be collected to determine amino acid concentrations, anabolic signaling and myofibrillar protein synthesis rates during the trials.
The purpose of the study is to quantify and compare the serum amino acid profile, and muscle protein synthesis rates, in response to consuming isonitrogenous amounts of ground meat (beef and pork) or plant-based alternatives -(soy and pea protein-based patties). Specific aim 1: Describe the post-prandial amino acid profile in serum in the 3 hours following consumption of the following four burger patties, in quantities calculated to deliver 20 grams of protein: ground beef, ground pork, Beyond Meat® burger, and tofu burger. Specific aim 2: Compare the ability of these four different foods to activate mTORC1 and protein synthesis in muscle.
Skeletal muscle quality is an important determinant of exercise performance and overall health. It is vital for not just movement, but also metabolizing nutrients. Protein from the diet can promote muscle protein synthesis for muscle recovery and growth. More importantly, doing so shifts net protein balance positively (e.g. protein synthesis is greater than protein breakdown) and promotes greater rates of muscle protein turnover. Leucine is an amino acid required to build muscle, but it also acts as a signaling molecule informing the muscle to start protein synthesis. Before reaching skeletal muscle, dietary protein is digested into small peptides and free amino acids. Rate of absorption from the intestine to the blood stream is significantly faster for peptides compared to amino acids. As amino acid availability in the blood is a precursor for muscle protein synthesis, our objective is to determine if the different absorption rates between free amino acid and peptides influence muscle protein synthetic and breakdown rates.
Using stable isotope methodology, investigators will determine the postabsorptive and postprandial muscle protein synthetic response in 60 female adults (Age 50-79, BMI: \<30 kg/m2) immediately after an acute bout of resistance exercise. Participants will be divided in to 5 groups of twelve women (n=12). Each group will receive a different protein beverage or placebo to consume following the resistance exercise training. Group 1 will consume a beverage consisting of whey protein; group 2 will consume whey protein supplemented with additional leucine; group 3 will consume whey protein supplemented with additional leucine and hydrolyzed whey peptides; group 4 will consume whey protein supplemented with additional leucine and citrulline; group 5 will just consume water. During the testing, blood and muscle samples will be collected.