Hormonal

Co-ingesting 10g of citrulline with 15g of whey protein does not enhance myofibrillar protein synthesis (MPS) or blood flow in elderly men compared to 15g of whey protein alone, despite increasing arginine levels.

For elderly men, adding 10g of citrulline to a small dose of protein (15g) after exercise does not boost muscle building or blood flow any more than the protein alone. To maximize muscle protein synthesis, consume a larger dose of high-quality protein (like 45g of whey) instead of relying on citrulline to make a small dose work better.