Simmons, Erin Elizabeth (2018-08). Integration of Total Daily Protein Intake and Timing of Protein Supplementation on Muscle Anabolism during Simulated Elite Athlete Training in Fit Young Males. Doctoral Dissertation.
Thesis
A great deal of variation exists in recommendations of total daily protein intake and timing of supplementation for athletes. The most widely accepted recommendations promote protein intakes for strength and power athletes of 1.6-1.8 grams/kg/day and post-exercise protein supplementation. To our knowledge, no studies have investigated an interaction between supplementation timing and total daily needs in athletic populations. In an effort to determine optimal protein intake and supplementation strategies for athletic populations in a stable training phase, a double blind randomized controlled trial was conducted on 46 young, trained males (21.8+-3.1 yr, 182.2+-6.2 cm, 83.5+-13.6 kg). Subjects underwent a two-week familiarization period followed by the two-week intervention period, both consisting of concurrent sprint interval and resistance exercise with nutritional interventions of low (LO = 1.3 g/kg total mass/day, 1.9 g/kg lean mass/day) and high (HI = 2.2 g/kg total mass/day, 2.7 g/kg lean mass/day) daily protein intake and whey protein supplementation either immediately (IPE) or three hours delayed (DPE) post-exercise. An age and activity matched control group (CON) completed food and activity logs but continued their normal diet (1.6 g/kg total mass/day, 2.1 g/kg lean mass/day) and exercise regimens and did not perform exercise on the experimental day. Tests of body composition, power, and strength were conducted before and after the intervention period. Cumulative muscle protein synthesis (C-MPS) was determined using deuterium stable isotope labeling (70%2H2O, 3ml/kg) to measure myofibrillar fractional synthetic rates (myoFSR) during the 24-hour post exercise window. A two-way ANOVA (total protein x timing) showed no difference in myoFSR among groups. No differences in total body %fat or lean mass were found, but changes in thigh %fat (p=0.002), total thigh fat mass (p<0.001), and thigh cross section fat mass (p=0.049) were significantly greater in LO/DPE compared to CON. Knee extension one-repetition-maximum was significantly greater at follow-up in LO/DPE compared to CON (p=0.006) and change in knee extension 1RM was greater in HI/DPE compared to CON (p=0.006). Thus, trained individuals undergoing simulated elite athlete training exhibited no significant differences in muscle protein synthesis, lean mass accretion, or performance measures regardless of total daily protein intake or supplementation timing strategy.
