Thread: BCAA's??
View Single Post
Old 01-05-2009, 08:25 AM   #14
Mike ODonnell
Senior Member
Mike ODonnell's Avatar
Join Date: Nov 2006
Posts: 3,560

Originally Posted by Chris H Laing View Post
Thanks for the answer, but why might they be more effective pre workout? I thought BCAA's were just broken down proteins...but I know very little about BCAA's other than that other people use them and they work.
Timing of amino acid-carbohydrate ingestion alters anabolic response of muscle to resistance exercise
Kevin D. Tipton1,2, Blake B. Rasmussen1,2, Sharon L. Miller1,2, Steven E. Wolf1, Sharla K. Owens-Stovall1, Bart E. Petrini1, and Robert R. Wolfe1,2

1 Department of Surgery, University of Texas Medical Branch, and 2 Metabolism Unit, Shriners Hospitals for Children, Galveston, Texas 77550

The present study was designed to determine whether consumption of an oral essential amino acid-carbohydrate supplement (EAC) before exercise results in a greater anabolic response than supplementation after resistance exercise. Six healthy human subjects participated in two trials in random order, PRE (EAC consumed immediately before exercise), and POST (EAC consumed immediately after exercise). A primed, continuous infusion of L-[ring-2H5]phenylalanine, femoral arteriovenous catheterization, and muscle biopsies from the vastus lateralis were used to determine phenylalanine concentrations, enrichments, and net uptake across the leg. Blood and muscle phenylalanine concentrations were increased by ~130% after drink consumption in both trials. Amino acid delivery to the leg was increased during exercise and remained elevated for the 2 h after exercise in both trials. Delivery of amino acids (amino acid concentration times blood flow) was significantly greater in PRE than in POST during the exercise bout and in the 1st h after exercise (P < 0.05). Total net phenylalanine uptake across the leg was greater (P = 0.0002) during PRE (209 42 mg) than during POST (81 19). Phenylalanine disappearance rate, an indicator of muscle protein synthesis from blood amino acids, increased after EAC consumption in both trials. These results indicate that the response of net muscle protein synthesis to consumption of an EAC solution immediately before resistance exercise is greater than that when the solution is consumed after exercise, primarily because of an increase in muscle protein synthesis as a result of increased delivery of amino acids to the leg.
Fitness Spotlight
The IF Life
Mike ODonnell is offline   Reply With Quote