Luc van Loon is a researcher in the fields of exercise science, sports nutrition, and muscle metabolism. His published research focuses on dietary protein requirements, muscle protein synthesis rates, and the metabolic effects of exercise. He also investigates the impacts of amino acid supplementation and resistance training on muscle mass and recovery across diverse populations, including athletes, older adults, and clinical patients.
A single meal containing 20 grams of high-quality protein maximizes muscle protein synthesis for up to 4 to 6 hours.
"if you consider that a single meal containing 20 grams of a high-quality protein maximizes muscle protein synthesis for up to 4 to 6 hours, then it makes the most sense that every main meal throughout today is an anabolic stimulus" (said at 0:30:39)
Dose-response tracer studies in healthy young adults show that ~20 g (or ~0.25-0.30 g/kg) of high-quality, rapidly digested protein is sufficient to maximize myofibrillar and mixed muscle protein synthesis (MPS) at rest and after isolated resistance exercise. However, higher amounts (up to 40 g) can stimulate higher rates of MPS following whole-body resistance exercise or in older adults. Furthermore, the acute elevation of MPS following an isolated 20 g dose of fast-digesting protein typically peaks around 60-90 minutes and returns toward baseline by 2-3 hours (the 'muscle full' effect), whereas complex mixed meals or larger doses may sustain aminoacidemia and whole-body protein balance for 3-5 hours.
- context: The response of muscle protein synthesis following whole-body resistance exercise is great… (Physiological reports 2016) · cited 187x in the literature
"The currently accepted amount of protein required to achieve maximal stimulation of myofibrillar protein synthesis (MPS) following resistance exercise is 20-25 g... Overall (groups combined), MPS was stimulated to a greater extent following ingestion of 40 g (0.059 ± 0.020%·h(-1)) compared with 20 g (0.049 ± 0.020%·h(-1); P = 0.005) of protein." (abstract, conclusions)
pubmedfull study (doi) - context: International Society of Sports Nutrition Position Stand: protein and exercise. (Journal of the International Society of Sports Nutrition 2017)
"General recommendations are 0.25 g of a high-quality protein per kg of body weight, or an absolute dose of 20-40 g. Acute protein doses should strive to contain 700-3000 mg of leucine and/or a higher relative leucine content, in addition to a balanced array of the essential amino acids (EAAs). These protein doses should ideally be evenly distributed, every 3-4 h, across the day." (abstract, conclusions)
pubmedfull study (doi) - supports: Maximizing Post-exercise Anabolism: The Case for Relative Protein Intakes. (Frontiers in nutrition 2019) · cited 89x in the literature
"Dose-response studies in average (i.e., ~80 kg) males have reported an absolute 20 g dose of high quality, rapidly digested protein maximizes mixed, and myofibrillar protein synthetic rates." (abstract, results, passage verified)
pubmedfull study (doi)
Growth hormone, especially when combined with anabolic steroids, increases connective tissue protein synthesis.
"we know that, especially from abuse of course, that growth hormone, in combination with, for example, anabolic steroids can help you with the connective tissue protein synthesis" (said at 2:06:56)
Recombinant human growth hormone (rhGH) robustly stimulates collagen and connective tissue protein synthesis in human tendons and skeletal muscle, without increasing myofibrillar (contractile) protein synthesis. However, attributing connective tissue synthesis especially to the combination with anabolic steroids is misleading: anabolic androgenic steroids primarily increase myofibrillar protein synthesis rather than connective tissue synthesis, and high doses of anabolic steroids have been shown in animal and human studies to alter collagen remodeling, decrease collagen synthesis enzymes, or increase tendon stiffness and rupture risk.
- contradicts: The effects of anabolic steroids on collagen synthesis in rat skeletal muscle and tendon. … (The American journal of sports medicine 1992) · cited 37x in the literature
"In the Achilles tendon, the activity of prolyl 4-hydroxylase and the hydroxyproline concentration decreased significantly (P less than 0.05) in the group given high doses at 3 weeks. Anabolic steroid treatment seems to have at least a transitory effect on collagen biosynthesis in male rat muscle and tendon; in tendon this effect is seen only with high doses." (abstract, results, passage verified)
pubmedfull study (doi) - supports: Growth hormone stimulates the collagen synthesis in human tendon and skeletal muscle witho… (The Journal of physiology 2010) · cited 205x in the literature
"Thus, increased GH availability stimulates matrix collagen synthesis in skeletal muscle and tendon, but without any effect upon myofibrillar protein synthesis. The results suggest that GH is more important in strengthening the matrix tissue than for muscle cell hypertrophy in adult human musculotendinous tissue." (abstract, results, passage verified)
pubmedfull study (doi) - supports: GH/IGF-I axis and matrix adaptation of the musculotendinous tissue to exercise in humans. (Scandinavian journal of medicine & science in sports 2012) · cited 32x in the literature
"Studies in humans with pathologically high levels of GH/IGF-I, and in healthy humans who receive either weeks of GH administration or acute injection of IGF-I into connective tissue, demonstrate increased expression and synthesis of collagen in muscle and tendon. These observations support a stimulatory effect of GH/IGF-I on the connective tissue in muscle and tendon, which appears far more potent than the effect on contractile proteins of skeletal muscle." (abstract, results, passage verified)
pubmedfull study (doi)