Nutrition for Optimal Strength Gains Keith Baar University of California Davis @MuscleScience
Muscle Mass and AgingSarcopenia – “poverty of flesh” the degenerative loss of skeletal muscle mass and strength associated with aging
mTORC1 and Muscle HypertrophyBaar & Esser Am J Physiol. 1999, 276:C120. There is a correlation between the activity of mTORC1 6h after a single bout of ResEx and hypertrophy over 6 weeks of training.
mTORC1 Regulation in Skeletal Muscle Growth Factors Activity Amino Acids mTORC1 Oxidation SIRT1 Alcohol High Fat AMPK Diet
Protein QuantityMuscle Protein Synthesis (% h-1) 0.15 0.10 0.05 0.00 0 10 20 30 40 Egg Protein Ingested (g)Moore et al Am J Clin Nutr. 2009, 89:161. The MPS response to oral amino acid supplementation plateaus at 20-25g (~8-10g essentials)
Protein SourceTang et al J Appl Physiol 107: 987–992, 2009 The amount of leucine in the blood and the increase in MPS is greater in response to whey than soy, or caesin
SIRT1 Blocks Muscle Growth Hypertrophy (% Diff) 160 * 120 80 0.053 40 0 GroupPhilp et al unpublished. Loading in the absence of SIRT1 results in a doubling of muscle growth compared to wild type (overexpression decreases growth).
Practical Summary1. Strength is determined in large part by the size of the skeletal muscle.2. Our ability to grow muscle is dependent on mTOR and the subsequent increase in protein synthesis.3. To maximize mTOR activity, protein synthesis, and muscle growth take 20-25g protein (8-10g essentials) in a rapidly, digestible high available leucine, form soon after ResEx.4. To keep mTOR activity and protein synthesis high for as long as possible take antioxidants, don’t drink alcohol or consume a high fat diet, and don’t do endurance exercise for at least 18 hours.