King Grub
2012-07-19, 11:35
We undertook two crossover-designed studies to characterise plasma AA responses to the intake of 20 g of protein. In study 1, fifteen untrained and overnight fasted subjects consumed 20 g protein from skim milk, soy milk, beef steak, boiled egg, and a liquid meal supplement. In study 2, 10 fasted endurance-trained subjects consumed 20 g protein serve from a protein-rich sports bar at rest and after a 60 min submaximal ride. Plasma AAs concentrations were measured immediately before, and for 180 min after food ingestion using a gas chromatography- flame ionisation detection technique. A pharmacokinetic analysis was undertaken for profiles of total AAs (TAA), essential AAs (EAA), branched chain AAs (BCAA) and leucine. Although Area under the Curve values for plasma TAA was similar across protein sources, the pattern of aminoacidemia showed robust differences between foods, with liquid forms of protein achieving peak concentrations twice as quickly after ingestion than solid protein-rich foods (e.g. ~50 min vs ~ 100 min), and skim milk achieving a significantly faster peak leucine concentration than all other foods (~ 25 min). The completion of exercise prior to ingestion of protein sources did not cause statistically significant changes in the pattern of delivery of key AAs, BCAAs and leucine apart from a 20-40% increase in the rate of elimination. These results may be useful to plan the type and timing of intake of protein-rich foods to maximise the protein synthetic response to various stimuli such as exercise.
Int J Sport Nutr Exerc Metab. 2012 Jul 4. Effect of Intake of Different Dietary Protein Sources on Plasma Amino Acid Profiles at Rest and After Exercise.
Int J Sport Nutr Exerc Metab. 2012 Jul 4. Effect of Intake of Different Dietary Protein Sources on Plasma Amino Acid Profiles at Rest and After Exercise.