The Effect of Dietary Protein on Protein Metabolism and Performance in Endurance-trained Males

Recommendations for dietary protein are based primarily intakes that maintain nitrogen (i.e. protein) balance rather than optimize metabolism and/or performance. PURPOSE To determine how varying protein intakes, including a new tracer-derived safe intake, alter whole body protein metabolism and exercise performance during training. METHODS Using a double-blind randomized crossover design, 10 male endurance-trained runners (age, 32±8 yr; VO2peak, 65.9±7.9 ml O2·kg-1·min-1) performed 3 trials consisting of 4 days of controlled training (20, 5, 10, 20 km·d-1, respectively) while consuming diets providing 0.94 (LOW), 1.20 (MOD), and 1.83 (HIGH) g protein·kg-1·d-1. Whole body protein synthesis (S), breakdown (B), and net balance (NB) were determined by oral [15N]glycine on the first and last day of the 4-d controlled training period whereas exercise performance was determined from maximum voluntary isometric contraction (MVC), 5-km Time Trial (5kmTT), and countermovement jump Impulse (IMP) and peak force (PF) before and immediately after the 4-d intervention. RESULTS S and B were not affected by protein intake whereas NB showed a dose-response (HIGH > MOD > LOW, P

from Sports Medicine via xlomafota13 on Inoreader https://ift.tt/2NDJPKh
via IFTTT