its possible thats possible. but its guess work. theres lots of feed back loops to control blood glucose levels. but assuming you did already get your insulin spike naturally, then right after that you got your humalog to get in... then yes i guess you could have two types of insulin. but who is to say you dont already get both types during every humalog injection(in healthy people). no one knows for sure exactly what is going on inside the body of a non diabetic using exogenous insulin(as far as natural insulin secretion goes). not only that, but also you are off base with you "10 minutes till shake is digested" idea. even simple carb like dextrose isnt fully digested in 10 minutes time. you will have it entering the blood at aorund 10 minutes, with a steady stream for the next half hour or so, depending on total carb intake. if i recall correctly, the maximum rate of digestion for glucose is about 110grams per hour.
