Originally Posted by Carbonfiberboy

Well, there is this:
https://pubmed.ncbi.nlm.nih.gov/21399532/
plus other similar studies. The thing to watch for in these sorts of studies is if the two concoctions being compared are isocaloric. My typical 200 Cal./hr drink is 14% protein, so that's 7g protein per hour. I doesn't seem like that's going to present any digestive difficulty, does it? I figure it's sorta like the idea that consuming carbs during a ride reduces the amount one needs to eat after a ride. Same thing with protein.

Note that those pros drink a huge protein shake immediately after riding.