Recently the question was raised as to whether or not adding milk to a post-workout concoction (i.e. whey-based) would be detrimental or inhibitory to the proven benefits. The question was immediately greeted with what we've all accepted as true: that adding a milk-based protein (i.e. casein) to whey will slow the digestion and absorption of whey.

This is a belief that I have, in the past, prescribed to as well, and, to this day, I still recommend only mixing the rapid digesting and absorbing ingredients contained in a post-workout concoction with agua.

However, I have been rethinking this somewhat. For example, when we have a beautfiul protein blend that contains whey isolate, milk isolate and calcium caseinate--or better yet, we mix whey in with cottage cheese--don't we get a large, acute hyperaminoacidemia from the whey and a moderate, longer-lasting hyperaminoacidemia from the casein? If this is true, then the benefits of whey are not negated by the casein.

This is my line of thinking and seems to be what I gather from JB's Bedtime Story. In addition, this is the premise behind the highly overpriced Night-Time proteins. In addition, the classic Boire Protein Utilization study(1) demonstrates this quite clearly.

I'm not at all saying that I recommend milk with a post-workout drink. Nor am I trying to debate what the best post-workout nutrition entails I am simply trying to bring forth an issue that I think requires a bit more clarification. This is something that applies throughout the day, and the post-workout example was simply an illustration.

1. Slow and fast dietary proteins differently modulate postprandial protein accretion. Boirie Y, Dangin M et al. Proc. Natl. Acad. Sci 94 (1007) 14930-35