Dr. Burd鈥檚 area of research interest is nutrition and exercise metabolism. Our research group commonly uses stable isotope tracers of amino acids to understand how exercise, nutrition, or disease may regulate skeletal muscle mass (e.g., protein synthesis). However, this method also traces the metabolic fate of amino acids at the whole body level (e.g., protein synthesis, breakdown, and oxidation). Protein ingestion and exercise are the two main anabolic stimuli to human skeletal muscle tissue for maximizing net muscle protein balance. Thus, the application of nutrition and exercise physiology approaches provides an understanding of the mechanisms regulating skeletal muscle mass under various human conditions.