Research

Hormonal

Ingestion of whey protein hydrolysate stimulates mixed muscle protein synthesis (MPS) to a significantly greater degree than micellar casein or soy protein isolate in young men, both at rest and following resistance exercise.

If you are looking to maximize muscle growth after resistance training, choose whey protein hydrolysate over casein or soy. The study shows whey stimulates muscle protein synthesis significantly more (up to 122% more than casein) because it digests faster and provides a quicker spike in leucine, which triggers muscle building. Ensure you consume about 20-25g of whey protein (providing ~10g of essential amino acids) immediately after your workout.

GoodSupportsHIGH confidence
We conclude that the feeding-induced simulation of MPS in young men is greater after whey hydrolysate or soy protein consumption than casein both at rest and after resistance exercise; moreover, despite both being fast proteins, whey hydrolysate stimulated MPS to a greater degree than soy after resistance exercise.
Jason E. Tang et al. · Journal of Applied Physiology · 2009

Why this rating

Randomized controlled trial with direct measurement of MPS via stable isotopes, though sample size is small (n=6 per group).

Source

Ingestion of whey hydrolysate, casein, or soy protein isolate: effects on mixed muscle protein synthesis at rest and following resistance exercise in young men

Jason E. Tang et al. · Journal of Applied Physiology · 2009

DOI 10.1152/japplphysiol.00076.2009

rct · n=18Cited 979×
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DOI resolved against Crossref · corpus check 2026-06-10

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