-Net muscle protein balance (NBAL): metabolic basis for change in muscle mass
-Balance between protein synthesis and degradation determines the amount of protein in muscle
-Balance of synthesis and breakdown of muscle contractile (myofibrillar proteins)
-Positive balance = accretion of muscle proteins
-Negative balance = loss of muscle proteins
-Nutritional intake and exercise affect the duration and magnitude of these balance periods
Figure 1: Muscle protein gains are due to the accumulation of muscle protein in response to each individual bout of resistance exercise plus nutrient (amino acid) intake. For illustration purposes, the theoretical daily response to resistance exercise plus ingestion of a meal at weeks 1, 12 and 24 of training is depicted. There is no change in basal NBAL or in the response to a meal plus exercise over time, but instead muscle hypertrophy results from an accumulation of proteins due to the response to each individual exercise bout. The positive area in response to exercise plus nutrient intake is greater than the negative areas during fasting. (http://www.pponline.co.uk/encyc/recommended-protein-intake-build-muscle-mass-40541)
GAINING MUSCLE MASS II
-Genetics determines the possible amount of muscle mass gain for any individual
-Also, environmental influences such as exercise and nutrition
-Resistance exercise increases muscle protein synthesis in improved muscle protein balance
-Without amino acids, protein muscle cannot reach positive levels (Muscle Anabolism: positive levels of muscle protein balance)
-Protein ingestion before or after exercise causes positive muscle anabolism
NITROGEN BALANCE
-Protein requirements determined by nitrogen balance
-Protein is unique nutrient as it contains nitrogen
-Athletes that want increased muscle mass should have positive nitrogen balance
-When nitrogen balance is measured in athletes
-The greater the protein intake, the greater the nitrogen balance
(http://www.pponline.co.uk/encyc/recommended-protein-intake-build-muscle-mass-40541)
AMINO ACIDS AND MUSCLE MASS
-As little as 6g of essential amino acids consumed either before or after exercise result in positive net balance
-Leucine may be the most important amino acid for stimulation of muscle protein synthesis [Along with isoleucine and valine are branched-chain amino acids (BCAA); BCAAs are “most anabolic amino acids”]
-Animal studies show that leucine stimulates pathways inside muscle cells resulting in increased muscle protein synthesis after intense exercise
From: http://www.pponline.co.uk/encyc/recommended-protein-intake-build-muscle-mass-40541
GLUTAMINE SUPPLEMENTS
-Candow et al studied glutamine supplementation in resistance training young adults.
+31 subjects were divided in 2 groups.
+One group recieved glutamine ( 0.9 g / kg lean tissue mass) and the other group recieved maltodextrin ( 0.9 g / kg lean tissue mass).
+Before and after, 1 repetition maximum (1 RM) of squats, bench press and peak knee extension were measured.
+Measurements of lean tissue mass and urinary measurements of muscle degradation were also made.
+The strength training program consisted for 6 weeks.
-The study showed that strength training increased (of course) strength and lean tissue mass.
-The study could not show any differences between the groups.
-That means that glutamine supplementation failed to show any additional effects on strength and lean body mass in this study.
From: http://www.ironmag.com/articles/supplements/2004_cml_glutamine.htm
