Pro PerformanceŽ PM Protein contains a 60:40 ratio of fast (whey) and slow (casein), absorbing proteins.  The amino acids and peptides from whey protein move through the digestive system and into your bloodstream quickly while casein proteins "clots" in the digestive system and are much more slowly digested.  Casein, therefore, takes longer to get to the blood stream then whey.

The Benefits of Casein and Whey Blend
The balance between protein synthesis and protein breakdown is very important.  Recently a study has shown that whey protein consumption will result in a rapid rise in blood amino acids and create a quick and short-lived increase in protein synthesis*  Although this does stimulate protein synthesis, it has no impact on protein break down.  Casein, however will lead to a small but steady increase in blood amino acids for at least 7 hours.  This stimulates protein synthesis to a smaller extent than whey, but it significantly decreases protein breakdown.**+

Glutamine
Pro Performance PM Protein is enhanced with 2 grams of Glutamine.  By itself, glutamine serves as fuel for the immune system, may provide an anti-catabolic effect and is involved in protein synthesis.+  Prolonged high-intensity exercise has been shown to decrease glutamine levels, which makes glutamine a favorite among serious workout enthusiasts.

*Slow and fast dietary proteins differently modulate post-parndial protein accretion.  Proceedings of the National Academy of Sciences.  94:14930-14935, 1997

**The digestion rate of protein is an independent regulating factor of postprandial protein retention.  American Journal of Physiology [Endocrinology and Metabolism] 280(2):E340-348, 2001